Coronary artery aneurysms (CAAs) are uncommon in coronary angiography, and left main coronary artery aneurysms are rare. There is no consensus for the treatment of CAAs. A young patient with left coronary artery aneurysm diagnosed by coronary angiography and with recurrent acute myocardial infarction was treated with rivaroxaban and aspirin. The patient had no angina for 6 months. Novel oral anticoagulants combined with antiplatelet agents may be appropriate for the treatment of CAAs.