Eighteen patients whose mean age was 61 years were referred to us with acute aortic occlusion from 1977 to 1985. Ten patients had cardiac emboli (group I) and eight had aortoiliac occlusive disease (group II). Fourteen of these patients had paresis or paralysis. Diagnosis was prompt but the time lapse from onset of symptoms to revascularization averaged 18 hours (group I, 10.3 hours; group II, 26.1 hours). All 10 patients in group I had embolectomy alone; of the eight patients in group II, two had transfemoral thrombectomy and six had bypass procedures. The perioperative mortality rate was 40% in group I and 62.5% in group II. Complications developed in 12 patients (nine died); renal failure occurred in 11, compartment syndrome in nine, adult respiratory disease syndrome in three, acute myocardial infarction in three, disseminated intravascular coagulation in two, and paraplegia in one. No amputations were required in the nine survivors and limb function was restored in eight of these patients. Acute aortic occlusion sets in motion a chain of events that threatens life and limb. Prompt diagnosis and revascularization by the simplest operation are required to decrease morbidity and mortality.