Acute arterial occlusion secondary to embolization from aneurysms located upstream occurred in 16% in 277 aneurysms involving subclavian, abdominal aortic, femoral, and popliteal vessels. This association should be suspected in those instances when the occlusive symptoms are severe and sudden in onset. The study emphasizes the importance of aortic outlining, as well as arteriographic mapping of both lower extremities, when occlusive disease of one or both legs is present. An aneurysm upstream should be suspected when there is failure of a previously implanted graft peripherally. Asymptomatic, small abdominal aortic aneurysms should be resected.