Coronary artery aneurysm (CAA) is a relatively rare disease that may cause angina, myocardial infarction, sudden death due to thrombosis, embolisation, or rupture. This report describes the case of a man aged 65 years old who had an anterior myocardial infarction due to left anterior descending artery (LAD) aneurysm. We attempted early percutaneous transluminal coronary angioplasty (PTCA) for treatment of acute myocardial infarction, but were not successful. He was then treated with intracoronary streptokinase. Serial coronary angiographies showed recanalisation and aneurysm on the LAD. The patient was operated on with coronary bypass surgery, and treated with an oral anticoagulant, nitrate, and blocker. He was well after one year of follow-up.