Coronary sinus ostial atresia (CSOA) with persistent left superior vena cava (PLSVC) is a rare cardiovascular anomaly. Although usually asymptomatic, it is of critical importance to recognize this anomaly before cardiac surgery, particularly in patients with a functional single ventricle because ligation or division of the PLSVC may lead to lethal myocardial edema, ischemia and necrosis. To the best of our knowledge, preoperative recognition of this anomaly on cardiac CT has not been reported. We report an infant with functional single ventricle in whom CSOA and PLSVC were successfully demonstrated on preoperative cardiac CT.