This prospective study was conducted to correlate the presence of angiographically significant coronary artery disease (CAD) and atherosclerotic disease in the aorta, carotid, and femoral arteries as measured by ultrasound. One hundred two consecutive patients admitted for coronary angiography for suspected CAD participated in the study. All patients underwent transesophageal echocardiography for the evaluation of thoracic aortic atherosclerosis and B-mode ultrasound for evaluation of carotid and femoral atherosclerosis. Intimal-medial thickness > 1 mm in the thoracic aorta or peripheral vessels was considered as evidence of atherosclerosis. Patients with CAD (n = 64) had a significantly higher incidence of atherosclerotic plaques in the thoracic aorta, carotid, and femoral arteries than subjects with normal coronary arteries: 91%, 72%, 77% vs 31%, 47% and 42%, respectively. Extracoronary plaque was a stronger predictor of CAD than conventional risk factors. Evidence of plaque in patients younger than median age (64 years) had a higher specificity than in patients above median age (77% vs 40%, respectively, p <0.0001). Plaque score of the extracardiac vessels was significantly higher in patients with multivessel CAD than in patients with 1-vessel CAD disease and in subjects with normal coronary arteries (p <0.001). Thus, atherosclerotic plaques in the aortic and femoral arteries and, to a lesser extent, in the carotid arteries are strong predictors of CAD.