This case report describes a 72-year-old man with a rare congenital right coronary artery–pulmonary artery fistula associated with severe coronary atherosclerosis. During coronary bypass surgery, the fistula was not only ligated but its distal segment was innovatively used as an arterial graft to revascularize the right marginal branch. The patient had excellent postoperative results, with patent grafts and 11 years of symptom-free follow-up