Data regarding long-term outcomes after the arterial switch operation for D-transposition of the great arteries are scarce. A single-institution retrospective cohort study was conducted to assess cardiovascular outcomes after an arterial switch operation between 1983 and 1999. Patients without follow-up visits within 3 years were contacted and secondary sources of information obtained. Overall, 400 patients, 154 (38.3%) with a ventricular septal defect, 238 (59.5%) with an intact septum, and 9 (2.3%) with a Taussig-Bing anomaly, were followed for a median of 18.7 years. In perioperative survivors, overall and arrhythmia-free survival rates at 25 years were 96.7±1.8% and 96.6±0.1%, respectively. Late mortality was predominantly a result of sudden deaths and myocardial infarction. At 25 years, 75.5±2.5% remained free from surgical or catheter-based reintervention. Freedom from an adverse cardiovascular event was 92.9±1.9% at 25 years. Independent predictors were a single right coronary artery (hazard ratio, 4.58; 95% confidence interval, 1.32-15.90), P=0.0166) and postoperative heart failure (hazard ratio, 6.93; 95% confidence interval, 1.57-30.62; P=0.0107). At last follow-up, the left ventricular ejection fraction was 60.3±8.9%, 97.3% had class I symptoms, and 5.2% obstructive coronary artery disease. Peak oxygen uptake was 35.1±7.6 mL/kg/min (86.1±15.1% predicted), with a chronotropic index <80% in 34.2%. At least moderate neoaortic and pulmonary regurgitation were present in 3.4% and 6.6%, respectively, and more than mild neoaortic and pulmonary stenosis in 3.2% and 10.3%. Long-term and arrhythmia-free survival is excellent after arterial switch operation. Although sequelae include chronotropic incompetence and neoaortic, pulmonary, and coronary artery complications, most patients maintain normal systolic function and exercise capacity.