Carotid duplex ultrasonography is the noninvasive procedure of choice for evaluating ECAD. However, carotid angiography should be performed before doing carotid endarterectomy. Multivariate logistic regression analysis showed that significant prognostic variables for ECAD in an elderly population are (1) cigarette smoking, (2) serum total cholesterol, (3) serum HDL cholesterol (inverse association), (4) diabetes mellitus, and (5) prior CAD. Patients with 80-100% ECAD develop a higher incidence of ABI and TIA than patients with 40-80% ECAD. Patients with 40-80% ECAD develop a higher incidence of ABI and TIA than patients with 0-40% ECAD. Patients with ECAD have a higher prevalence of prior CAD and develop a higher incidence of new coronary events than patients without ECAD. In patients with ECAD, significant prognostic variables for new coronary events are (1) silent ischemia, (2) prior CAD, (3) serum HDL cholesterol (inverse association), and (4) cigarette smoking. Risk factors for ECAD and CAD should be treated in patients with ECAD. Cigarette smoking must be stopped. Hypertension, dyslipidemia, and diabetes mellitus should be treated. Aspirin, 325 mg/d, should be administered to patients with ECAD. Ticlopidine hydrochloride, 250 mg two times per day should be considered in patients with ECAD who are unable to tolerate aspirin or who develop cerebrovascular events on aspirin. Carotid endarterectomy should be considered in symptomatic patients with 70-99% ECAD.