Saccular aortic aneurysms are eccentrically shaped and are commonly thought to be the consequence of infection of the aorta. However, saccular-type aneurysms can be found independent of any clinical or subclinical infection and can be associated with a penetrating aortic ulcer. Moreover, penetrating aortic ulcers have been described in the thoracic aorta, but there is a paucity of any documentation of this clinical and pathologic entity occurring in the abdominal aorta. The authors describe 2 cases of symptomatic, penetrating atherosclerotic ulcers of the abdominal aorta causing saccular, noninfectious abdominal aortic aneurysms.