Fetal and neonatal Ebstein's anomaly has a poor prognosis, and there are few contemporary reviews of management and outcomes. This study retrospectively reviewed a management algorithm promoting early ductal closure after anatomic pulmonary obstruction had been excluded or relieved in neonatal Ebstein's anomaly from 1995 to 2004. Twenty-eight patients with Ebstein's anomaly were identified, 9 prenatally (8 with hydrops) and 19 postnatally, at a median age of <24 hours. Celermajer index scores predicted a mortality rate of 35%. Prostaglandins were administered to 24 of 28 patients. Prostaglandins were continued for obstructive lesions in 9 until the relief of pulmonary outflow obstructions or aortic coarctation repair. In 8 of 9 patients, prostaglandins were discontinued after intervention. One patient continued receiving prostaglandins until a Blalock-Taussig shunt was performed 3 weeks after surgical valvotomy. Prostaglandins were discontinued in 17 of 24 patients with uneventful ductal constrictions. The ductus arteriosus persisted in 5 patients with hemodynamic instability, of whom 4 underwent ductal ligation, with immediate improvement. In 1 of 24 patients, unrecognized right ventricular outflow tract obstructions became apparent when prostaglandins were discontinued. Prostaglandins were restarted until a primary superior cavopulmonary anastomosis was performed at 7 weeks. The median follow-up period of 26 survivors was 34 months (range 3 to 106), 4 after bidirectional superior cavopulmonary anastomoses and 1 after a Fontan procedure. In conclusion, in neonatal Ebstein's anomaly of the tricuspid valve, prolonged patency of the ductus arteriosus in patients without anatomic outflow tract obstructions is deleterious. "Circular shunts" may develop in patients with pulmonary and tricuspid insufficiency. The ligation or spontaneous constriction of the ductus arteriosus may result in hemodynamic improvement. This approach to neonatal Ebstein's anomaly of the tricuspid valve has yielded a substantial reduction in mortality to 7% in a high-risk cohort.