Two randomized, prospective, placebo controlled trials have reported the impact of inhaled nitric oxide (INO) term/near term infants with respiratory failure. The NINOS trial demonstrated that INO decreases the incidence of death/need for ECMO from 64% in the control group to 46% and the other study reported a reduction in the need for ECMO from 71% in the control group to 40% in the INO treated group. Although these two trials have shown that INO decreases the need for ECMO, a 40% need for ECMO despite INO therapy is very high. Sub-analysis of the NINOS trial data suggests that further reductions in death/need for ECMO are possible with early use of INO in the study population. In addition, analyses of weaning strategy used in the NINOS trial and another study specifically addressing dose response seem to indicate that optimum therapeutic effect is seen at doses of 1 to 20 ppm of NO. This study tests the hypothesis that use of INO in term/near term infants requiring mechanical ventilation for respiratory failure and an oxygenation index (OI) of =15 and <25 will decrease the probability of death before discharge/receiving ECMO from 35% in the control group to 20% in the early INO group, a relative reduction of 43%. The hypothesis will be tested in a prospective, randomized, double masked manner and will compare the use of INO with a control group who do not receive INO while at the lower OI. Infants in either group who have no response to study gas and show subsequent deterioration with OI = 25 will receive open label INO therapy as part of their medical management. Presently, open label INO is offered when the OI is = 25. Infants with IO = 25 who have not been randomized into the study may receive open-label INO under this protocol.