Ischemic changes and acute or subacute cardiac failure after arterial switch operation generally result!; from imperfect transfer of coronary arteries to the neoaorta. Peroperative and early postoperative myocardial ischemia is the main cause of death in these patients. We present an unusual cause of myocardial ischemia. and cardiac failure after arterial switch: a congenital coronary artery fistula between the circumflex artery and the right ventricle. The symptoms imitate coronary translocation failure. In differential diagnosis of the coronary perfusion problems encountered after the arterial switch operation, coronary artery fistula should not be forgotten, although it is rare. (c) 2005 Elsevier B.V. All rights reserved.