The recent results of two major multicenter trials, ECST (European Carotid Surgery Trialists') and NASCET (North American Symptomatic Carotid Endarterectomy Trial), show benefit of carotid endarterectomy for patients with recent (4-6 months), nondisabling, carotid distribution, cerebral ischemic events (hemispheric and retinal TIA or stroke) and ipsilateral severe (70-99%) carotid stenosis provided that perioperative mortality remains low. ECST, in addition, failed to demonstrate the benefit of surgery for patients with mild stenosis (0-29%). The comparisons between the studies in regards to methodology, measurements, and complications are discussed.