Several case series have suggested that endarterectomy is beneficial in asymptomatic carotid artery disease. Four randomized trials have been done in this area, the most recent of which is the Asymptomatic Carotid Atherosclerosis Study (ACAS). Results of the first three trials were negative, and ACAS produced a tantalizing, statistically significant finding that does not translate into clinical importance. Disabling strokes have not been reduced by surgical therapy, and the benefit for women has not been shown. It is unclear from this study whether persons with the greatest stenosis and the highest vascular risk profiles are appropriate candidates for endarterectomy. In patients in whom carotid artery disease is incidentally discovered, the benefits of the prophylactic addition of carotid endarterectomy to coronary bypass grafting or other major surgical procedure in patients are still unknown. Excellent surgical skill is of paramount importance for the future use of this procedure. Mass population screening to detect asymptomatic carotid disease will only be justified when and if future studies identify patients in whom the risk for disabling stroke after the procedure is clearly reduced.