This study of 1,612 diabetic patients was undertaken to determine whether the extent of coronary artery disease in diabetics with lower- extremity arterial disease (263 patients) differed from extent in those without (1,349 patients). Long-term follow-up was also studied. After adjustment for baseline differences, no significant difference in coronary artery disease extent was found between the two groups. On the other hand, patients with lower-extremity disease had a significantly poorer prognosis than those without. Lower-extremity arterial disease thus was an independent predictor of mortality among diabetics who had coronary artery disease.