Coronary artery aneurysms are a rare condition with left-main trunk aneurysms occurring in only about 0.1 % of the population. We report on a giant left-main coronary artery aneurysm in a young male status post two previous open-heart operations. The aneurysm was successfully treated by patch occlusion of the ostial orifice and coronary revascularization of the left anterior descending and circumflex arteries.