From 1965 to 1974, 53 children with coarctation of the aorta (COA) and an associated ventricular septal defect (VSD) underwent cardiac catheterization. Thirty-one patients presented with congestive heart failure. Twenty-five of 27 patients (92%) who underwent cardiac catheterization under age 3 months had either systemic hypertension, a systolic gradient across the coarctation greater than 20 mm Hg or both. Pulmonary hypertension was present in all 25 patients. COA repair was performed in 39 patients and there were seven deaths. Of the 32 survivors, 23 have no residual gradient; six are normotensive but have a mild residual gradient; three are hypertensive or have a gradient greater than 20 mm Hg. Repair of the VSD or pulmonary artery banding has been performed in 11 of 44 patients who survived infancy. Spontaneous closure of the VSD has occurred in three cases and 25 patients have a small VSD that does not warrant surgical repair. Surgical repair of COA during infancy may be unavoidable but conservative medical management of the associated VSD is often successful.