opinion: Mr. Justice Brennan
  delivered the opinion of the Court.
  Appellants are graduates of schools of chiropractic who seek to practice in Louisiana without complying with the educational requirements of the Louisiana Medical Practice Act, Title 37, La. Rev. Stat. §§ 1261-1290. They brought this action against respondent Louisiana State Board of Medical Examiners in the Federal District Court for the Eastern District of Louisiana, seeking an injunction and a declaration that, as applied to them, the Act violated the Fourteenth Amendment. A statutory three-judge court invoked, sua sponte, the doctrine of abstention, on the ground that “The state court might effectively end this controversy by a determination that chiropractors are not governed by the statute,” and entered an order “staying further proceedings in this Court until the courts of the State of Louisiana shall have been afforded an opportunity to determine the issues here presented, and retaining jurisdiction to take such steps as may be necessary for the just disposition of the litigation should anything prevent a prompt state court determination.” 180 F. Supp. 121, 124.
  Appellants thereupon brought proceedings in the Louisiana courts. They did not restrict those proceedings to the question whether the Medical Practice Act applied to chiropractors. They unreservedly submitted for decision, and briefed and argued, their contention that the Act, if applicable to chiropractors, violated the Fourteenth Amendment. The state proceedings terminated with a decision by the Louisiana Supreme Court declining to review an intermediate appellate court’s holding both that the Medical Practice Act applied to chiropractors and that, as so applied, it did not violate the Fourteenth Amendment. 126 So. 2d 51.
  Appellants then returned to the District Court, where they were met with a motion by appellees to dismiss the federal action. This motion was granted, on the ground that “since the courts of Louisiana have passed on all issues raised, including the claims of deprivation under the Federal Constitution, this court, having no power to review those proceedings, must dismiss the complaint. The proper remedy was by appeal to the Supreme Court of the United States.” The court saw the case as illustrating “the dilemma of a litigant who has invoked the jurisdiction of a federal court to assert a claimed constitutional right and finds himself remitted to the state tribunals.” The dilemma, said the court, was that “On the one hand, in view of Government & Civic Employees Organizing Committee v. Windsor, 353 U. S. 364, ... he dare not restrict his state court case to local law issues. On the other, if, as required by Windsor, he raises the federal questions there, well established principles will bar a relitigation of those issues in the United States District Court. . . . Since, in the usual case, no question not already passed on by the state courts will remain, he is thereby effectively deprived of a federal forum for the adjudication of his federal claims.” 194 F. Supp. 521, 522. Appellants appealed directly to this Court under 28 U. S. C. § 1253, and we noted probable jurisdiction. 372 U. S. 904. We reverse and remand to the District Court for decision on the merits of appellants’ Fourteenth Amendment claims.
  There are fundamental objections to any conclusion that a litigant who has properly invoked the jurisdiction of a Federal District Court to consider federal constitutional claims can be' compelled, without his consent and through no fault of his own, to accept instead a state court’s determination of those claims. Such a result would be at war with the unqualified terms in which Congress, pursuant to constitutional authorization, has conferred specific categories of jurisdiction upon the federal courts, and with the principle that “When a Federal court is properly appealed to in a case over which it has by law-jurisdiction, it is its duty to take such jurisdiction .... The right of a party plaintiff to choose a Federal court where there is a choice cannot be properly denied.” Willcox v. Consolidated Gas Co., 212 U. S. 19, 40. Nor does anything in the abstention doctrine require or support such a result. Abstention is a judge-fashioned vehicle for according appropriate deference to the “respective competence of the state and federal court systems.” Louisiana P. & L. Co. v. Thibodaux, 360 U. S. 25, 29. Its recognition of the role of state courts as the final expositors of state law implies no disregard for the primacy of the federal judiciary in deciding questions of federal law. Accordingly, we have on several occasions explicitly recognized that abstention “does not, of course, involve the abdication of federal jurisdiction, but only the postponement of its exercise.” Harrison v. NAACP, 360 U. S. 167, 177; accord, Louisiana P. & L. Co. v. Thibodaux, supra, 360 U. S., at 29.
  It is true that, after a post-abstention determination and rejection of his federal claims by the state courts, a litigant could seek direct review in this Court. NAACP v. Button, 371 U. S. 415; Lassiter v. Northampton County Board of Elections, 360 U. S. 45. But such review, even when available by appeal rather than only by discretionary writ of certiorari, is an inadequate substitute for the initial District Court determination — often by three judges, 28 U. S. C. § 2281 — to which the litigant is entitled in the federal courts. This is true as to issues of law; it is especially true as to issues of fact. Limiting the litigant to review here would deny him the benefit of a federal trial court’s role in constructing a record and making fact findings. How the facts are found will often dictate the decision of federal claims. “It is the typical, not the rare, case in which constitutional claims turn upon the resolution of contested factual issues.” Townsend v. Sain, 372 U. S. 293, 312. “There is always in litigation a margin of error, representing error in factfind-ing ....” Speiser v. Randall, 357 U. S. 513, 525. Thus in cases where, but for the application of the abstention doctrine, the primary fact determination would have been by the District Court, a litigant may not be unwillingly deprived of that determination. The possibility of appellate review by this Court of a state court determination may not be substituted, against a party’s wishes, for his right to litigate his federal claims fully in the federal courts. We made this clear only last Term in NAACP v. Button, supra, 371 U. S., at 427, when we said that “a party has the right to return to the District Court, after obtaining the authoritative state court construction for which the court abstained, for a final determination of his claim.”
  We also made clear in Button, however, that a party may elect to forgo that right. Our holding in that case was that a judgment of the Virginia Supreme Court of Appeals upon federal issues submitted to the state tribunals by parties remitted there under the abstention doctrine was “final” for purposes of our review under 28 U. S. C. § 1257. In so determining, we held that the petitioner had elected “to seek a complete and final adjudication of [its] rights in the state courts” and thus not to return to the District Court, and that it had manifested this election “by seeking from the Richmond Circuit Court ‘a binding adjudication’ of all its claims and a permanent injunction as well as declaratory relief, by making no reservation to the disposition of the entire case by the state courts, and by coming here directly on certio-rari.” 371 U. S., at 427-428. We fashioned the rule recognizing such an election because we saw no inconsistency with the abstention doctrine in allowing a litigant to decide, once the federal court has abstained and compelled him to proceed in the state courts in any event, to abandon his original choice of a federal forum and submit his entire case to the state courts, relying on the opportunity to come here directly if the state decision on his federal claims should go against him. Such a choice by a litigant serves to avoid much of the delay and expense to which application of the abstention doctrine inevitably gives rise; when the choice is voluntarily made, we see no reason why it should not be given effect.
  In Button, we had no need to determine what steps, if any, short of those taken by the petitioner there would suffice to manifest the election. The instant case, where appellants did not attempt to come directly to this Court but sought to return to the District Court, requires such a determination. The line drawn should be bright and clear, so that litigants shunted from federal to state courts by application of the abstention doctrine will not be exposed, not only to unusual expense and delay, but also to procedural traps operating to deprive them of their right to a District Court determination of their federal claims. It might be argued that nothing short of what was done in Button should suffice — that a litigant should retain the right to return to the District Court unless he not only litigates his federal claims in the state tribunals but seeks review of the state decision in this Court. But we see no reason why a party, after unreservedly litigating his federal claims in the state courts although not required to do so, should be allowed to ignore the adverse state decision and start all over again in the District Court. Such a rule would not only countenance an unnecessary increase in the length and cost of the litigation; it would also be a potential source of friction between the state and federal judiciaries. We implicitly rejected such a rule in Button, when we stated that a party elects to forgo his right to return to the District Court by a decision “to seek a complete and final adjudication of his rights in the state courts.” We now explicitly hold that if a party freely and without reservation submits his federal claims for decision by the state courts, litigates them there, and has them decided there, then — whether or not he seeks direct review of the state decision in this Court — he has elected to forgo his right to return to the District Court.
  This rule requires clarification of our decision in Government Employees v. Windsor, 353 U. S. 364, the case referred to by the District Court. The plaintiffs in Windsor had submitted to the state courts only the question whether the state statute they challenged applied to them, and had not “advanced” or “presented” to those courts their contentions against the statute’s constitutionality. We held that “the bare adjudication by the Alabama Supreme Court that the [appellant] union is subject to this Act does not suffice, since that court was not asked to interpret the statute in light of the constitutional objections presented to the District Court. If appellants’ freedom-of-expression and equal-protection arguments had been presented to the state court, it might have construed the statute in a different manner.” 353 U. S., at 366. On oral argument in the instant case, we were advised that appellants’ submission of their federal claims to the state ¡courts had been motivated primarily by a belief that Windsor required this. The District Court likewise thought that under Windsor a party is required to litigate his federal question in the state courts and “dare not restrict his state court case to local law issues.” 194 F. Supp., at 522. Others have read Windsor the same way. It should not be so read. The case does not mean that a party must litigate his federal claims in the state courts, but only that he must inform those courts what his federal claims are, so that the state statute may be construed “in light of” those claims. See Note, 73 Harv. L. Rev. 1358, 1364-1365 (1960). Thus mere compliance with Windsor will not support a conclusion, much less create a presumption, that a litigant has freely and without reservation litigated his federal claims in the state courts and so elected not to return to the District Court.
  We recognize that in the heat of litigation a party may find it difficult to avoid doing more than is required by Windsor. This would be particularly true in the typical case, such as the instant one, where the state courts are asked to construe a state statute against the backdrop of a federal constitutional challenge. The litigant denying the statute’s applicability may be led not merely to state his federal constitutional claim but to argue it, for if he can persuade the state court that application of the statute to him would offend the Federal Constitution, he will ordinarily have persuaded it that the statute should not be construed as applicable to him. In addition, the parties cannot prevent the state court from rendering a decision on the federal question if it chooses to do so; and even if such a decision is not explicit, a holding that the statute is applicable may arguably imply, in view of the constitutional objections to such a construction, that the court considers the constitutional challenge to be without merit.
  Despite these uncertainties arising from application of Windsor — which decision, we repeat, does not require that federal claims be actually litigated in the state courts — a party may readily forestall any conclusion that he has elected not to return to the District Court. He may accomplish this by making on the state record the “reservation to the disposition of the entire case by the state courts” that we referred to in Button. That is, he may inform the state courts that he is exposing his federal claims there only for the purpose of complying with Windsor, and that he intends, should the state courts hold against him on the question of state law, to return to the District Court for disposition of his federal contentions. Such an explicit reservation is not indispensable; the litigant is in no event to be denied his right to return to the District Court unless it clearly appears that he voluntarily did more than Windsor required and fully litigated his federal claims in the state courts. When the reservation has been made, however, his right to return will in all events be preserved.
  On the record in the instant case, the rule we announce today would call for affirmance of the District Court’s judgment. But we are unwilling to apply the rule against these appellants. As we have noted, their primary reason for litigating their federal claims in the state courts was assertedly a view that Windsor required them to do so. That view was mistaken, and will not avail other litigants who rely upon it after today’s decision. But we cannot say, in the face of the support given the view by respectable authorities, including the court below, that appellants were unreasonable in holding it or acting upon it. We therefore hold that the District Court should not have dismissed their action. The judgment is reversed, and the case is remanded for further proceedings consistent with this opinion.
  It is so ordered.
  The action was brought in 1957. The District Court initially dismissed the complaint on the authority of Louisiana State Board of Medical Examiners v. Fife, 162 La. 681, 111 So. 58, aff’d per curiam, 274 U. S. 720. The Court of Appeals for the Fifth Circuit reversed, 259 F. 2d 626, on petition for rehearing, 263 F. 2d 661. We denied certiorari, 359 U. S. 1012. On remand the three-judge District Court was convened.
  Appellants did not challenge the order of abstention by appeal here. See Turner v. City of Memphis, 369 U. S. 350; 28 U. S. C. § 1253. Nor do they now challenge it. Thus there is not before us any question as to either the proper scope of the abstention doctrine or the propriety of its application to this case.
  Appellants’ petition in the Louisiana trial court appended a copy of the abstention order and opinion and recited that the state proceeding was brought “in pursuance of and obedience to” the abstention order. Like the complaint filed in the federal court, the petition sought both declaratory and injunctive relief. The allegations were that the Medical Practice Act was inapplicable to chiropractors and also “In the alternative, in the event the court should hold that the Medical Practice Act does apply to your plaintiffs . . . said Act is unconstitutional” because in violation of the Fourteenth Amendment. The petition challenged the statute’s validity under that Amendment in terms substantially identical to those in the federal court complaint. The trial court, on the basis of the same documentary evidence that had been submitted to the three-judge District Court, sustained appellees’ defense of “no cause of action.”
  Appellants made no attempt to obtain appellate review of the state court decision in this Court. See Lassiter v. Northampton County Board of Elections, 360 U. S. 45; NAACP v. Button, 371 U. S. 415; 28 U. S. C. § 1257 (2).
  At least this is true in a ease, like the instant one, not involving the possibility of unwarranted disruption of a state administrative process. Compare Burford v. Sun Oil Co., 319 U. S. 315; Alabama Public Service Comm’n v. Southern R. Co., 341 U. S. 341.
  See Kurland, Toward a Co-operative Judicial Federalism: The Federal Court Abstention Doctrine, 24 F. R. D. 481, 487.
  The doctrine contemplates only “that controversies involving unsettled questions of state law [may] be decided in the state tribunals preliminary to a federal court’s consideration of the underlying federal constitutional questions,” City of Meridian v. Southern Bell Tel. & Tel. Co., 358 U. S. 639, 640; “that decision of the federal question be deferred until the potentially controlling state-law issue is authoritatively put to rest,” United Gas Pipe Line Co. v. Ideal Cement Co., 369 U. S. 134, 135-136; “that federal courts do not decide questions of constitutionality on the basis of preliminary guesses regarding local law,” Spector Motor Service, Inc., v. McLaughlin, 323 U. S. 101, 105; “that these enactments should be exposed to state construction or limiting interpretation before the federal courts are asked to decide upon their constitutionality,” Harrison v. NAACP, 360 U. S. 167, 178.
  Even where fact findings on federal constitutional contentions are for state tribunals to make in the first instance, as in state criminal prosecutions, they are not immune, when brought into question in federal habeas corpus, from District Court consideration and, in proper cases, from de novo consideration. Townsend v. Sain, 372 U. S. 293, 312-319.
  Cf. Wright, The Abstention Doctrine Reconsidered, 37 Tex. L. Rev. 815, 825 (1959).
  One case has even permitted the litigant to return to the District Court although review was sought and denied here. See Tribune Review Publishing Co. v. Thomas, 153 F. Supp. 486, aff’d, 254 F. 2d 883, where the litigant’s federal claims were decided by the District Court following decision upon the same claims by the Pennsylvania Supreme Court and denial by us of certiorari to that court’s judgment. Mack v. Pennsylvania, 386 Pa. 251,126 A. 2d 679, cert. denied, 352 U. S. 1002.
  See Note, 59 Col. L. Rev. 749, 773 (1959); Note, 73 Harv. L. Rev. 1358, 1364 (1960), quoting brief for appellant, p. 5, in Lassiter v. Northampton County Board of Elections, 360 U. S. 45.
  It has been suggested that state courts may “take no more pleasure than do federal courts in deciding cases piecemeal . . .” and “probably prefer to determine their questions of law with complete records of cases in which they can enter final judgments before them.” Clay v. Sun Ins. Office, 363 U. S. 207, 227 (dissenting opinion). We are confident that state courts, sharing the abstention doctrine’s purpose of “furthering the harmonious relation between state and federal authority,” Railroad Comm’n v. Pullman Co., 312 U. S. 496, 501, will respect a litigant’s reservation of his federal claims for deci- . sion by the federal courts. See Spector Motor Service, Inc., v. Walsh, 135 Conn. 37, 40-41, 61 A. 2d 89, 92. However, evidence that a party has been compelled by the state courts to litigate his federal claims there will of course preclude a finding that he has voluntarily done so. And if the state court has declined to decide the state question because of the litigant’s refusal to submit without reservation the federal question as well, the District Court will have no alternative but to vacate its order of abstention.
  The reservation may be made by any party to the litigation. Usually the plaintiff will have made the original choice to litigate in the federal court, but the defendant also, by virtue of the removal jurisdiction, 28 U. S. C. § 1441 (b), has a right to litigate the federal question there. Once issue has been joined in the federal court, no party is entitled to insist, over another’s objection, upon a binding state court determination of the federal question. Thus, while a plaintiff who unreservedly litigates his federal claims in the state courts may thereby elect to 'forgo his own right to return to the District Court, he cannot impair the corresponding right of the defendant. The latter may protect his right by either declining to oppose the plaintiff’s federal claim in the state court or opposing it with the appropriate reservation. It may well be, of course, that a refusal to litigate or a reservation by any party will deter the state court from deciding the federal question.
  The District Court’s abstention order, in instructing appellants to obtain a state court determination not of the state question alone but of “the issues here presented,” was also misleading.
choices: comity: civil rights comity: criminal procedure comity: First Amendment comity: habeas corpus comity: military comity: obscenity comity: privacy comity: miscellaneous comity primarily removal cases, civil procedure (cf. comity, criminal and First Amendment); deference to foreign judicial tribunals assessment of costs or damages: as part of a court order Federal Rules of Civil Procedure including Supreme Court Rules, application of the Federal Rules of Evidence, Federal Rules of Appellate Procedure in civil litigation, Circuit Court Rules, and state rules and admiralty rules judicial review of administrative agency's or administrative official's actions and procedures mootness (cf. standing to sue: live dispute) venue no merits: writ improvidently granted no merits: dismissed or affirmed for want of a substantial or properly presented federal question, or a nonsuit no merits: dismissed or affirmed for want of jurisdiction (cf. judicial administration: Supreme Court jurisdiction or authority on appeal from federal district courts or courts of appeals) no merits: adequate non-federal grounds for decision no merits: remand to determine basis of state or federal court decision (cf. judicial administration: state law) no merits: miscellaneous standing to sue: adversary parties standing to sue: direct injury standing to sue: legal injury standing to sue: personal injury standing to sue: justiciable question standing to sue: live dispute standing to sue: parens patriae standing standing to sue: statutory standing standing to sue: private or implied cause of action standing to sue: taxpayer's suit standing to sue: miscellaneous judicial administration: jurisdiction or authority of federal district courts or territorial courts judicial administration: jurisdiction or authority of federal courts of appeals judicial administration: Supreme Court jurisdiction or authority on appeal or writ of error, from federal district courts or courts of appeals (cf. 753) judicial administration: Supreme Court jurisdiction or authority on appeal or writ of error, from highest state court judicial administration: jurisdiction or authority of the Court of Claims judicial administration: Supreme Court's original jurisdiction judicial administration: review of non-final order judicial administration: change in state law (cf. no merits: remand to determine basis of state court decision) judicial administration: federal question (cf. no merits: dismissed for want of a substantial or properly presented federal question) judicial administration: ancillary or pendent jurisdiction judicial administration: extraordinary relief (e.g., mandamus, injunction) judicial administration: certification (cf. objection to reason for denial of certiorari or appeal) judicial administration: resolution of circuit conflict, or conflict between or among other courts judicial administration: objection to reason for denial of certiorari or appeal judicial administration: collateral estoppel or res judicata judicial administration: interpleader judicial administration: untimely filing judicial administration: Act of State doctrine judicial administration: miscellaneous Supreme Court's certiorari, writ of error, or appeals jurisdiction miscellaneous judicial power, especially diversity jurisdiction