Coronary artery fistula (CAF) is a rare congenital anomaly that can be associated with intracardiac shunts, endocarditis, myocardial infarction, or coronary aneurysms. Recent reports have emphasized the efficacy of early closure either by percutaneous transcatheter or open surgical techniques. The purpose of this article is to review a case of 43 year-old male who presented for repair of a giant aneurysmal left main coronary artery fistula emptying into the right atrium. The giant aneurysm fistula dilatation was maximally measured to be 4.3 cm x 3.5 cm. There was clear left pulmonary vein compression and the giant size raised the question of aneurysm. With its unpredictable nature and patient’s worsening symptoms and physical activity limitation, a direct ligation of fistulous tract was performed. Surgical management was safe treatment and efficacious.