Pulmonary hypertension and transient graft dysfunction may complicate the immediate postoperative course of patients undergoing lung transplantation. We report the effect of inhaled nitric oxide (NO) in a patient with pulmonary edema and severe hypoxemia in the period following bilateral lung transplantation. NO was delivered through the inspiratory line and its mean concentration was monitored in the trachea. PaO2/FiO2 improved from 65 to 105 with an NO concentration of 1 ppm, but no further improvement was obtained by increasing the dose to 5 ppm. Pulmonary vascular resistance (PVR) decreased from a baseline value of 251 dynes-sec/cm5 to a low of 213 dynes-sec/cm5 with NO administration. A slight increase in PVR seems to have been the main factor limiting the therapeutic efficacy of inhaled NO in this case.