Aneurysms of the left main coronary artery (LMCAA) are extremely uncommon, with an incidence of 0.1%. The main etiologic factor is atherosclerosis. Other causes include connective tissue disorders, trauma, vasculitis, congenital, mycotic, and idiopathic. These dilated sections of coronary artery are not benign pathology because they are subject to spasm, thrombosis, and subsequent distal embolism, spontaneous dissection and rupture. Treatment options include anticoagulation, custom-made covered stents, reconstruction, resection and exclusion with bypass. Our report on a young case illustrates the potential complication of LMCAA and presents its management.