retrograde femoral interlocking nail in complex fractures retrograde interlocking nail was used as the method of fixation in 35 different cases of combination of complex femoral fractures we performed this procedure in fractures of femoral shaft associated with fracture neck femur pathological fractures of proximal third of femur with trochanteric pathology ipsilateral fracture of femur and tibia in polytrauma cases with multiple other injuries in highly obese patients with fracture shaft femur this technique was also used in cases of pregnancy with fracture shaft femur and in unstable pelvic fracture or dislocation hip associated with fracture shaft femur operative technique involved with retrograde insertion of unreamed noncannulated custom made nail through entrance portal in intercondylar notch was applied for fixation of the shaft femur fracture the other associated fracture around hip was stabilized separately using suitable implant according to type of fracture in cases of ipsilateral fracture of femur and tibia femur was stabilized by retrograde interlocking nail and tibia was stabilized by antigrade interlocking nail through same incision at the same sitting the case was followed up for three years the average union time was 12 to 18 weeks out of 35 cases 31 cases regained full knee movement out of the remaining 4 cases 2 cases could regain up to 90 degrees of movement these were old fractures and noncooperative patients in one case patellofemoral arthritis was developed because of an operative error where a nail was not put inside the articular surface malunion was observed in an early case of the series and implant failure was nil retrograde interlocking nail was used as the method of fixation in complex fracture problems multiple fractures of long bones can be stabilized in one stage preventing multiple operations at different stages in polytraumatized patients this resulted in early recovery lesser hospital stay and early rehabilitation of patient with good results and is economical also