Pseudoaneurysms in the ascending aorta most commonly occur as a complication of surgical procedures at this site. They have also been reported in association with trauma, infection, aortitis, and other disorders. Pseudoaneurysm formation in the descending aorta or arch may occur as a result of penetrating ulcers in the presence of severe atherosclerotic plaque. Pseudoaneurysm as a result of atherosclerotic disease has only rarely been noted in the ascending aorta, where complex plaque is less common. We report here the finding with transesophageal echocardiography of a pseudoaneurysm in the ascending aorta as a result of atherosclerotic disease and penetrating ulcer.