In a consecutive series of 160 surgically treated abdominal aortic aneurysm, four patients with acute aortic thrombotic occlusion of an abdominal aortic or iliac aneurysm were encountered. Three of four aneurysms were 7cm in diameter or smaller. Also, 3 of 4 patients had chronic occlusive disease of legs. Our mortality rate was 75%. The recommendation is made that all abdominal aortic aneurysms be resected if there is substantial associated distal occlusive disease.