Nitric oxide (NO) represents a new therapeutic modality for treating neonatal pulmonary hypertension and may obviate the need for extracorporeal membrane oxygenation (ECMO) in a number of cases of neonatal respiratory failure. Recently, the authors treated an infant with a congenital diaphragmatic hernia and pulmonary hypertension with NO on two separate occassions. During the initial period of stabilization, NO failed to reverse the pulmonary hypertension and prevent the development of progressive respiratory failure. After a successful course of ECMO, recurrent pulmonary hypertension developed that was successfully treated with continuous low-dose NO therapy for over 1 month. Prolonged administration of NO in varying doses titrated to clinical and echocardiographic parameters was well tolerated by the infant and prevented the need for a second run of ECMO.