Peripheral arterial disease (PAD) is a growing and often underdiagnosed health problem that predicts cardiovascular events and mortality. Estimating its prevalence in the general population is a major issue for assessing health needs and planning health services. The aim of this study was to determine the prevalence of PAD and its risk factors in an urban Mexican population. A random sample of 400 adult subjects was selected from a Family Medical Unit of the Mexican Institute of the Social Security. Clinical examination was performed and a questionnaire was applied to all subjects. After an overnight fast, serum glucose, triglyceride, and cholesterol concentrations were measured. Blood pressure was taken and the ankle-brachial index (ABI) was calculated by Doppler examination in both sides. PAD was diagnosed if one of the ABIs was less than 0.90. Prevalence was estimated with 95% confidence intervals (CI95%), and odds ratios (OR) with CI95% were obtained to assess association with some atherogenic risk factors in a multiple logistic regression analysis. The prevalence of PAD was 10.0% (CI95%, 7.24%-13.37%), and it was higher in men. Most subjects with PAD had no signs or symptoms, although the presence of either signs or symptoms was more frequent in subjects with PAD. The main risk factors related to PAD were serum triglycerides > or = 150 mg/dL (OR 2.25; CI95% 1.0-5.1), heavy smoking (OR 2.5; CI95% 0.9-6.7) and a history of diabetes mellitus for longer than 7 years (OR 1.9; CI95% 0.6-5.8). The prevalence of PAD is high in this Mexican urban population. Asymptomatic PAD may be highly frequent, and low-cost, noninvasive Doppler ultrasonography should be considered as an adequate screening procedure in primary care to detect individuals at high risk for major cardiovascular events.