The restenosis rates of 5% to 15% have been reported after carotid endarterectomy (CEA). We undertook this investigation to determine whether the routine practice of carotid artery patch closure and intraoperative completion duplex ultrasonography would result in lower rates of carotid restenosis after CEA. All consecutive carotid endarterectomies performed between 2000 and 2004 at a single institution were reviewed retrospectively. Patients underwent CEA using a longitudinal arteriotomy, followed by routine patching and intraoperative completion duplex ultrasonography. Only patients with at least one postoperative duplex scan performed at a minimum of 180 days after CEA were included. During the 5-year study period, 407 consecutive carotid endarterectomies were performed, with a combined 30-day stroke and mortality rate of 2.5%; 217 patients (53%) had one or more duplex ultrasound examinations performed at least 180 days after CEA. The mean follow-up duration was 692 days. Of the patients who underwent intraoperative intervention based on the results of the completion duplex study, none experienced restenosis, stroke, or death. CEA that is performed with routine patching and intraoperative duplex completion ultrasonography is a safe, durable operation with restenosis rates below those commonly reported.