Severe deformity or nonconfluence of the pulmonary arteries was repaired during correction of congenital heart defects by implantation of a complete, fresh, antibiotic-sterilized homograft pulmonary artery bifurcation in 17 patients, aged 15 months to 17 years. Six patients had Fallot's tetralogy; five, pulmonary atresia and ventricular septal defect; three, truncus arteriosus; two, ventricular septal defect; and one, pulmonary atresia with intact ventricular septum. All but one had previously undergone one or more palliative or corrective operations. Thirteen patients survived the operation (76%; 70% confidence interval = 61% to 88%) and were followed up from 2 to 56 months postoperatively (mean = 16 months). All had symmetrical pulmonary perfusion on chest x-ray films and satisfactory homograft function on Doppler echocardiograms. There were no late deaths or reoperations. Four patients (24%; 70% confidence interval = 12% to 39%) died in the hospital of pulmonary or cardiac dysfunction despite a technically satisfactory reconstruction. Comparison of predicted and observed ventricular pressure ratios in nine patients showed that the factor contributed by a right pulmonary artery branch stenois was cancelled in most. The use of a complete, adult-size homograft has thus facilitated reconstruction of the pulmonary artery bifurcation and given encouraging early results.