Twenty-six patients underwent reoperation for coarctation of the aorta (C of A) between 1972 and 1980. Most patients (73%) had undergone primary repair in infancy. The interval to reoperation was 5 months to 18 years (mean 8.2 years). Indications for reoperation included symptoms in 4, exercise systemic hypertension in 1, electrocardiographic changes of left ventricular strain in 1, arm hypertension in 21, and a C of A gradient at rest greater than 30 mm Hg in all. Surgical procedures included patch aortoplasty (16 patients), bypass graft (6 patients), left subclavian angioplasty (3 patients), and end-to-end anastomosis (1 patient). There were no operative complications or mortality. There was 1 late death from aortic valve disease. Duration of follow-up in the remaining 25 patients was 2 weeks to 7 years (mean 2.5 years). All patients are asymptomatic. C of A gradients were significantly reduced from 30 to 132 mm Hg (mean 56) preoperatively to 0 to 48 mm Hg (mean 15) postoperatively. Right arm systolic blood pressure also was significantly improved from 120 to 237 mm Hg (mean 153) preoperatively to 100 to 160 mm Hg (mean 124) postoperatively. Systemic systolic hypertension persisted in 5 of 25 (20%). It is concluded that C of A reoperation is a low risk procedure that improves symptoms and reduces C of A gradient and arm blood pressure. However, systolic hypertension does not always resolve postoperatively. Patch aortoplasty appears to be a safe and effective surgical approach.