The aim was to determine if certain risk factors in the general population are more strongly related to peripheral arterial disease than to ischemic heart disease. Arterial disease in the lower limbs was measured by means of the World Health Organization questionnaire on intermittent claudication, the ankle brachial pressure index, and a reactive hyperemia test in 1,592 men and women aged 55-74 years selected randomly in 1988 from the age-sex registers of 10 general practices in Edinburgh, Scotland. Peripheral arterial disease was strongly related to lifetime cigarette smoking, with additional risks in current and exsmokers of less than 5 years. Multiple regression of risk factors on measures of peripheral arterial disease showed associations with diabetes mellitus (but not impaired glucose tolerance), systolic blood pressure, and serum cholesterol; inverse association with high-density lipoprotein cholesterol; and only univariate association with triglycerides. In multiple logistic regressions of risk factors on six separate indicators of cardiovascular disease, the only consistent difference was that smoking increased the risk of peripheral arterial disease (range of odds ratios, 1.8-5.6) more than heart disease (range of odds ratios, 1.1-1.6). Diabetes mellitus was not a stronger risk factor for peripheral arterial disease.