Contemporary outcomes of complete atrioventricular septal defect (CAVSD) repair, particularly for defects with associated abnormalities, is unclear. The goal of this study is to report an all-inclusive experience of CAVSD repair using a consistent surgical approach. All patients undergoing CAVSD repair between 1995 and 2016 at our institution were included. Patients were divided into 2 groups: isolated and complex (tetralogy of Fallot, aortic arch repair, double outlet right ventricle, and total anomalous pulmonary venous return). Survival and reoperation were analyzed using log-rank test and Gray's test, respectively. Multivariable analysis was performed with Cox regression. Overall, 406 patients underwent repair: 350 (86%) isolated and 56 (14%) complex CAVSD (tetralogy of Fallot: 34, double outlet right ventricle: 7, aortic arch repair: 12, total anomalous pulmonary venous return: 3). Median age at repair was 5 months (range, 10 days to 16 years); 339 (84%) had trisomy 21. A 2-patch repair was used in 395 (97%) and the zone of apposition was completely closed in 305 (75%). Perioperative mortality was 2% and 4% in the isolated and complex groups, respectively. Perioperative mortality since 2006 was 0.9%. Median follow-up was 7 years. Overall 10-year survival and incidence of any reoperation were 92% and 11%, respectively. Complex anatomy was not a risk factor for mortality (p = 0.35), but it was for reoperation (hazard ratio [HR]: 2.6; p < 0.01). Risk factors for left atrioventricular valve reoperation were a second bypass run (HR: 2.7) and preoperative moderate or worse regurgitation (HR: 2.3). Mortality after CAVSD repair is low, yet reoperation remains a significant problem. Repair of complex CAVSD can be performed with similar mortality rates.