We report the successful use of Nifedipine in the treatment of acute pulmonary hypertension in an young child after a cardiac operation. This patient had undergone patch closure of large ventricular septal defect. She had signs of severe pulmonary artery hypertension unresponsive to hyperventilation, oxygenation, sedation, and a myriad of vas-oactive drugs. Nifedipine, 0.3mg /kg every 4 hours, effectively treated her pulmonary artery hypertension and allowed for a smooth postoperative course and positive outcome. The drug lowered systemic diastolic pressure, but not systolic pressure.