In 260 patients with myocardial infarction the systolic blood pressure gradient from arm to big toe was used as an indirect measure of the degree of generalized atherosclerosis. Arterial insufficiency was found in 12 per cent of the men and in 17 per cent of the women studied. The two year mortality was 19 per cent in males with arterial insufficiency as against 6 per cent in males without arterial insufficiency. This difference increased with longer (56-82 months) follow-up. The number of women was smaller but the results were similar. The present study does not support the theory that most patients with myocardial infarction have generalized atherosclerosis. Indeed, this seems to be the case in only a small fraction of such patients, thus supporting the idea that other mechanisms are also important in the etiology of myocardial infarction.