Atrial-level repair for transposition of the great arteries is one of the greatest achievements of modern cardiovascular medicine, transforming a once fatal congenital heart condition into one with excellent long-term survival. Although atrial-level repair has been supplanted by the arterial switch, there remains a population of patients who underwent atrial-level repair as children and now require ongoing care as adults. Survival slowly continues to decline in this population mainly owing to systemic right ventricular dysfunction and sudden death. Other problems include sinus node dysfunction, atrial arrhythmias, systemic atrioventricular valve regurgitation, baffle problems, and pulmonary hypertension. Evaluation and management of these late complications is addressed.