Three patients were treated for coronary artery-pulmonary artery fistula. Each was asymptomatic due to a coronary artery fistula. There was one instance each of myocardial infarction, mitral stenosis and a large closed ruptured aneurysm including a thrombus. All the fistulas were comprised of several small plexiform arranged vessels. The left to right shunt ratio was approximately 8 percent or less. A surgical operation was performed to close the drainage orifice of the fistulas through pulmonary arteriotomy under cardiopulmonary bypass in two patients while one patient underwent a ligation of a large abnormal vessel to the aneurysm followed by a resection of the aneurysm without cardiopulmonary bypass. A large saccular aneurysm of such fistulas is rare and a rupture of such an aneurysm is even more rare. The surgical management of coronary artery fistulas is also discussed herein.