Single coronary artery is a rare congenital anomaly of the coronary circulation which is often associated with other congenital cardiac malformations. Right coronary artery arising from the distal left circumflex artery is an extremely rare variety of single coronary artery. We report a patient with a single coronary artery system, in whom the right coronary artery originated from the distal left circumflex. No other associated cardiac anomaly was detected. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.