Coronary artery fistula, usually congenital in origin, is an abnormal communication between a coronary artery and a cardiac chamber or great vessel [coronary sinus, pulmonary artery, pulmonary vein, or super vena cava (SVC)]. A coronary fistula can produce high-output heart failure from volume overload and/or myocardial ischemia from coronary steal phenomenon. A 35-year-old man was found to have a large fistula from the left circumflex coronary artery to the SVC-right atrium junction, an extremely rare anomaly. This patient developed right ventricular dysfunction and chest pain due to myocardial ischemia in the left circumflex coronary artery distribution for several months before evaluation. Because of the large size of the fistula, surgical ligation was chosen instead of coil embolization to close the fistula. The patient was free of chest pain postprocedure. Coronary artery fistulas, though rare, should be considered in the differential diagnosis when a young patient presents with chest pain and/or heart failure. (C) 2011 Wiley Periodicals, Inc.