Because of the controversy concerning the ideal surgical repair for symptomatic coarctation of the aorta presenting in neonates and infants, our entire series of 179 children under the age of 12 months undergoing repair between January 1, 1976 and December 31, 1984 was reviewed. Of this group, 109 were neonates, 43 infants aged 31-90 days and 27 infants aged 90 days-12 months. Twenty patients had a simple coarctation and 159 had complex coarctation with additional intracardiac anomalies such as ventricular septal defect (37 patients also had pulmonary artery banding). One hundred and twenty-four were repaired with a subclavian flap operation, 32 with resection and end-to-end anastomosis and 23 with complex repairs (e.g. patch and reversed flap). Type of repair was the surgeon's choice and was selected on the basis of the anatomy of the coarctation. Total perioperative mortality was 15% (N = 27) while late mortality was 12% (N = 21). Twenty-one risk factors for mortality were evaluated by logistic analysis and the method of Cox. There was no risk difference between end-to-end versus subclavian flap repairs and all but one death occurred in patients with complex coarctations. Risk for in hospital death was increased by only one variable: the need for repair in the neonatal period. Risk for death in the first year of life was increased by the presence of congestive heart failure at initial presentation while later death correlated with intracardiac surgery. Recoarctation occurred in 28 patients (18.4%), all but 4 of these occurred in patients undergoing neonatal repairs.(ABSTRACT TRUNCATED AT 250 WORDS)