The incidence of the coronary artery aneurysm varies from 1.5-5%. Atherosclerosis is the most common cause of coronary artery aneurysm in adults. A discrete, giant, saccular atherosclerotic coronary artery aneurysm in an artery without significant proximal stenosis is rare. We report the first such case of a giant atherosclerotic coronary artery aneurysm successfully treated with coil embolization.