Although most patients with coronary artery aneurysms are asymptomatic, manifestations of myocardial ischemia may occur. However, the role that a coronary aneurysm may play in impairing arterial flow of an otherwise normal coronary circulation is not completely known. A 64-year-old woman with previous anteroseptal myocardial infarction was found to have a large aneurysm of the proximal left anterior descending (LAD) coronary artery without angiographic evidence of atherosclerotic disease. IVUS evaluation revealed an 18 mm long and 12.2 x 10.8 mm wide aneurysm without atherosclerosis, thrombus or calcification. Pulsed wave Doppler showed significant reduction of LAD flow reserve, which normalized after successful obliteration of the aneurysm with polytetrafluoroethylene (PTFE)-covered stent implantation. Severe in-stent graft restenosis was found at 7-month angiographic and intravascular ultrasound follow-up, which was managed successfully with minimally invasive direct coronary bypass surgery. The patient did well, without symptoms over the following year.