The prevalence of coronary artery disease (CAD) in patients with peripheral arterial disease (PAD) has been well defined. However, the prevalence of PAD in hospitalized patients with CAD has not been defined. The ankle-brachial index (ABI) is a useful non-invasive tool to screen for PAD. The aim of our study was to assess the prevalence of PAD in hospitalized patients with CAD by measuring the ABI. The study was conducted at the University of Wisconsin Hospital and Clinics inpatient Cardiovascular Medicine Service. Medically stable patients with CAD were invited to participate prior to hospital discharge. Data regarding cardiovascular risk factors, history of previous PAD, physical examination, and ABI were collected. An ABI less than or equal to 0.9 or a history of previous lower extremity vascular invention was considered to be indicative of significant PAD. A total of 100 patients (66 men and 34 women) were recruited. Forty patients were found to have PAD (mean ABI in non-revascularized patients with PAD = 0.67). By measuring the ABI, 37 (25 men) were positive for PAD and three had an ABI corrected with previous revascularization. Of these patients, 21 (52.5%) had previously documented PAD. Patients with PAD were older (p = 0.003), had a greater smoking history (p = 0.002), were more likely to have diabetes (p = 0.012), hypertension (p = 0.013) and a trend towards more dyslipidemia (p = 0.055). In conclusion, hospitalized patients with CAD are likely to have concomitant PAD. Risk factors for PAD in this patient population include advanced age, history of smoking, diabetes, hypertension, dyslipidemia and abnormal pulse examination. Identification of patients with PAD by measuring the ankle-brachial index is easily done.