From Jan. 1, 1983, to Jan. 1, 1988, 66 consecutive neonates with coarctation and severe hypoplasia of the transverse arch underwent coarctation repair by resection of the coarctation and reconstruction of the aortic arch. Mean age at operation was 14 ± 8 days, ranging from 2 to 30 days; 63% of the newborn infants were less than 2 weeks of age. The coarctation was isolated in 23%, associated with a ventricular septal defect in 39%, and associated with complex anomalies in 38%, including 16 cases of transposition of the great arteries or double-outlet right ventricle plus ventricular septal defect, two cases of simple transposition, two of corrected transposition plus ventricular septal defect, and five cases of ''hypoplastic'' left ventricle. The surgical technique comprises a wide resection of the coarctation extended to the contiguous ductal tissue followed by the reconstruction of the aortic arch in bringing the descending aorta into the concavity of the aortic arch. This technique is able to relieve the obstruction of the aortic arch provided that (1) the descending aorta is widely dissected to allow mobilization and (2) the incision of the transverse arch is extended proximal to the ostium of the left carotid artery. The operation was performed through a left thoracotomy in 62 patients and through a sternotomy in four additional neonates with transposition and ventricular septal defect who underwent a one-stage repair with aortic reconstruction, closure of the defect, and arterial switch. The overall early mortality rate (<30 days) was 14% (9/66; 95% confidence limits = 5% to 22%), including four deaths occurring within the first month, at a concomitant or subsequent repair of the associated anomaly. There were six late deaths, all related to the associated lesions. The overall mortality rate was 23% (15/66; 95% confidence limits = 13% to 33%). The mean follow-up was 21 ± 10 months, ranging from 6 to 66 months. Actuarial survival rates at 5 years are 72% ± 10% for the overall group; 87% ± 17% for simple coarctation; 88% ± 12% for coarctation and ventricular septal defect; and 52% ± 18% for complex coarctation. The rate of recurrent coarctation was 12.5% (95% confidence limits = 2% to 23%), leading to five reoperations with no deaths. Freedom from reoperation was 89.5% ± 9% at 5 years. This technique of coarctation repair offers several advantages: low operative mortality, complete relief of the left ventricular obstruction, wide resection of the ductus tissue, absence of prosthetic material, and preservation of the left subclavian artery.