Incidence and severity of risk factors were determined in 109 patients with peripheral vascular disease. Three anatomic groups were defined: group A (aortoiliac disease), group C, aortoiliac-femoropopliteal disease, and group L (femoropopliteal disease). Risk factors were studied in groups at differing ages, and sequentially in individuals. Patients in group A were significantly younger (average, 58 years) than in the other two groups (average, 65 to 66 years). Type II hyperlipoproteinemia occurred only in groups A and C. Type IV hyperlipoproteinemia and glucose intolerance were significantly more common in group L. Cigarette smoking was the most prominent risk factor in all groups (90% in groups A and C, 75% in group L). Onset of symptoms was eight to ten years earlier in smokers. Hypertension and electrocardiogram abnormalities were similar in all groups. Hypercholesterolemia often predated ischemia by many years, followed by normal lipid levels.