Coronary aneurysms represent anomalies identified in 0.15-4.9% of patients undergoing coronary angiography. At present there is no uniform definition of this pathology. According to current definitions, the term "aneurysm" refers to both diffuse over 150% dilation of the largest diameter of a coronary artery, and limited spherical or saccular dilation. Aneurysms are observed most commonly in the right coronary artery, and least frequently in the left main coronary artery. It has been demonstrated that atherosclerosis is the main cause of these anomalies in adults, and Kawasaki disease in children and adolescents. However, regardless of the pathogenesis of the aneurysm, pathology of the media of the blood vessel plays a major role in its formation. The most prevalent consequence of aneurysms in the coronary arteries is formation of a thrombus with distal embolization, vasospasm or vessel disruption at the site of wall injury. Therefore, therapeutic management in this anomaly involves both the prevention of thromboembolic complications and percutaneous or surgical closure of the aneurysm entry.