OBJECTIVE The outcome of surgical correction of atrioventricular septal defect with double-orifice left atrioventricular valve has improved in recent years but is still reported to be associated with high mortality and reoperation rates. Controversy exists about the management of the accessory orifice. We evaluated our results with correction of atrioventricular septal defect with double-orifice left atrioventricular valve. METHODS Between 1975 and 2006, 21 patients underwent correction of atrioventricular septal defect with double-orifice left atrioventricular valve. Clinical data were obtained by means of retrospectively reviewing inpatient and outpatient medical records. To evaluate the influence of double-orifice left atrioventricular valve on mortality and the need for reoperation, a comparison was made with 291 consecutive patients who, during the same period, underwent correction of atrioventricular septal defect without double-orifice left atrioventricular valve. RESULTS None of the 21 patients with double-orifice left atrioventricular valve had undergone a previous operation. The accessory orifice was managed with different techniques depending on the severity of the regurgitation. There was no in-hospital mortality, and there were 3 late deaths. Seven patients required 12 reoperations, 7 for left atrioventricular valve insufficiency. Double-orifice left atrioventricular valve had no influence on mortality but was a significant predictor for reoperation compared with repair of atrioventricular septal defect without double-orifice left atrioventricular valve. At the latest follow-up, all 18 survivors were in New York Heart Association functional class capital I, Ukrainian without medication. Only 1 patient showed residual mild left atrioventricular valve insufficiency. CONCLUSIONS Atrioventricular septal defect with double-orifice left atrioventricular valve can be repaired with low mortality. However, double-orifice left atrioventricular valve is a predictor for reoperation. The accessory orifice is often competent and should then be left untouched. If regurgitation of the accessory orifice is present, this is best managed with suture or patch closure.