In this study we sought to determine the prognostic factors that influence early and late survival after repair of partial atrioventricular canal and the need for reoperation. From January 1962 to January 1984, 199 patients underwent correction of partial atrioventricular canal. There were 73 male and 126 female patients, ranging in age from 5 months to 71 years (mean 11.2 years). Total 30 day operative mortality was 5.5%. Since 1980, the mortality has declined to 3%. Significant determinants of operative mortality were congestive heart failure, cyanosis, failure to thrive, age less than 4 years, and moderate-to-severe mitral valve insufficiency (p less than .01). Sex, cardiomegaly, radiographically increased pulmonary vasculature, intraoperative postrepair right ventricular-to-left ventricular pressure ratio, and pulmonary-to-systemic flow ratio were not significant in determining early mortality. Follow-up ranged from 1 to 21.4 years (mean 15.2). There were seven late deaths, primarily in older patients from atherosclerotic disease or malignancy. Late survival was 98% at 1 year and 96% at 20 years. Reoperation was performed on 18 patients, 15 for mitral incompetence, and three for subaortic stenosis. The need for reoperation correlated with severity of postrepair mitral insufficiency. Longterm survival is excellent after repair of the partial form of atrioventricular canal.