OBJECTIVE The goal of the study was to assess the prevalence and severity of symptomatic and asymptomatic carotid artery disease in patients with peripheral vascular disease (PVD). METHODS Consecutive patients with clinically and Doppler scanning-proven PVD (category 1 or greater) underwent prospective screening for the presence of carotid atherosclerosis with color-coded duplex ultrasonography. Preexisting risk factors were recorded with a standard questionnaire and included sex, age, diabetes mellitus, history of smoking, hypertension, prior stroke/transient ischemic attacks, and coronary artery disease. RESULTS Three hundred seventy-three consecutive patients were studied over 2 years. The mean age of the patients was 70 +/- 10 years; there were 223 (60%) men and 150 (40%) women; 71% of the patients had a history of smoking, 47% had coronary artery disease, 43% had hypertension, and 21% had diabetes mellitus. Two hundred eleven (57%) patients had 30% or greater carotid artery stenosis detected by carotid artery duplex scanning. Sixty-seven (32%) of these had symptoms of ischemic cerebral events, of whom 22 had potentially operable carotid artery stenoses (70% to 99%), whereas 72 of the 144 symptom-free patients had 60% to 99% stenosis. An additional 34 patients would be eligible candidates for the ongoing carotid endarterectomy trials (North American Symptomatic Carotid Endarterectomy Trial and European Carotid Surgery Trial). Although all the risk factors were associated significantly with PVD and carotid artery disease (p < 0.002), male sex and prior stroke/transient ischemic attack were the strongest predictors. CONCLUSIONS Routine carotid ultrasound screening of 373 consecutive patients with category I or greater PVD revealed that 22 patients with symptoms and 72 symptom-free patients were potential surgical candidates, representing 25% of the study cohort. An additional 34 patients were potential candidates for enrollment into the North American Symptomatic Carotid Endarterectomy Trial and European Carotid Surgery Trial.