Context.-The incidence of infective endocarditis after surgical repair of congenital heart defects is unknown. Objective.-To determine the long-term incidence of endocarditis after repair of any of 12 congenital heart defects in childhood. Design.-Population-based registry started in 1982. Setting.-State of Oregon. Participants.-All Oregon residents who underwent surgical repair for 1 of 12 major congenital defects at the age of 18 years or younger from 1958 to the present. Main Outcome Measure.-Diagnosis of infective endocarditis confirmed by hospital or autopsy records. Results.-Follow-up data were obtained from 88% of this cohort of 3860 individuals through 1993. At 25 years after surgery, the cumulative incidence of infective endocarditis was 1.3% for tetralogy of Fallot, 2.7% for isolated ventricular septal defect, 3.5% for coarctation of the aorta, 13.3% for valvular aortic stenosis, and 2.8% for primum atrial septal defect. In the cohorts with shorter follow-up, at 20 years after surgery the cumulative incidence was 4.0% for dextrotransposition of the great arteries; at 10 years, the cumulative incidence was 1.1% for complete atrioventricular septal defect, 5.3% for pulmonary atresia with an intact ventricular septum, and 6.4% for pulmonary atresia with ventricular septal defect. No children with secundum atrial septal defect, patent ductus arteriosus, or pulmonic stenosis have had infective endocarditis after surgery. Conclusion.-The continuing incidence of endocarditis after surgery for congenital heart defect, particularly valvular aortic stenosis, merits education about endocarditis prophylaxis for children and adults with repaired congenital heart defects.