Coronary artery aneurysms or ectasias are dilatations of arterial segments, which are typically incidentally identified at angiography. Although the etiology isn´t clearly established, several large clinical series described that the most common etiologic factor for coronary aneurysms is atherosclerotic coronary artery disease, but they can also be congenital or secondary to inflammatory or connective tissue disorders. A well-known association with Kawasaki disease is also studied. We review the case of a patient with acute coronary syndrome (ACS) and aneurysms dilations in coronary arteries, its diagnosis and therapeutic approach.