Since 1961, 35 patients have undergone correction of partial AV canal. The mean age was 9.8 years (2 to 56 years). At cardiac catheterization, the ratio of pulmonary to systemic blood flow was greater than 2.5: 1 in 26 patients (74%) while pulmonary artery pressure was greater than 30 mmHg in 18 patients (51%). Mitral regurgitation was mild in 14 patients, moderate in 8 and severe in 3. The defect was closed with a patch in all patients. Mitral valvuloplasty was performed in 23 patients (68%) and no patient required valve replacement. There were no hospital or late deaths. Postoperatively, 22 patients were asymptomatic (NYHA I) while 13 were class II. There was no progression of mitral regurgitation in 8 years mean follow-up.