Bilateral coronary artery fistulas originating from both right and left coronary arteries are rare congenital abnormalities. A 58-year-old man presented with chest pain unrelated to exertion. Coronary angiography showed a fistula originating from the level of the first diagonal branch of the left anterior descending (LAD) coronary artery and a 95% stenosis just distal to the fistula. Right coronary angiography showed another fistula originating from the ostium of the right coronary artery. Both fistulas drained into the pulmonary artery. Coronary bypass surgery was performed for the LAD lesion using the left internal mammary artery graft, during which both fistulas were ligated. No complications were encountered postoperatively.