Twenty-five infants under 1 year of age (mean, 10.3 weeks and 4.0 kg) underwent coarctation repair. Eight had ventricular septal defect (VSD), 3 had transposition of the great arteries with VSD, and 5 had severe tubular hypoplasia. One infant required mitral valve replacement, and 1 required repair of total anomalous pulmonary venous return. Fifteen had repair by primary anastomosis. Seven underwent Dacron or subclavian aortoplasty; the advantages and technique of angioplasty are reviewed. Three patients required bypass grafts. Seventeen patients survived operation. All 5 patients who had severe tubular hypoplasia died postoperatively. The mortality for repair of coarctation with VSD by simultaneous pulmonary artery banding was high; for coarctation with VSD we currently recommend repair without banding, followed by VSD closure if indicated. Three infants have been treated successfully in this manner, with early VSD closure in 1 and regression of the VSD during follow-up in 2. The 17 survivors have been followed for a mean of 41 months with 3 late deaths. Of the 17 survivors, all of whom had a primary anastomosis, 3 have residual gradients. Of the 11 survivors who had preoperative hypertension, 6 are still hypertensive; 3 of these have a gradient between the upper and lower extremities. It is striking that 3 have persistent hypertension despite repair under the age of 1 year.