We report a rare case of a giant coronary artery aneurysm with recurrent myocardial infarction (MI) in a 52-year-old man. He was admitted with severe chest pain and was diagnosed with acute MI. Ten days after thrombolysis, a transthoracic echocardiogram demonstrated a spherical mass apposed to the outer wall of the right atrium. Computed tomography with angiography showed this mass to be a huge aneurysm of the right coronary artery with a maximal diameter of 4 cm and filled with mural thrombus. Surgical resection of the aneurysm and coronary arterial bypass grafting were recommended. On day 60, while the patient awaited surgical treatment, recurrent MI caused by thrombotic occlusion occurred in the aneurysm site despite anticoagulant therapy. Two days after thrombolytic therapy, he underwent coronary artery bypass grafting and aneurysmal resection.