Purpose: This study examines the long-term results of a randomized prospective study comparing primary versus saphenous vein patch (VP) closure after carotid endarterectomy (CEA). Methods: One-hundred thirty-six patients undergoing 163 CEAs over a 46-month period were prospectively randomized to VP, or primary closure. Patients with internal carotid artery diameters less than 5 mm and those requiring complex CEAs underwent obligatory vein patch (OVP). Patients were monitored with duplex scanning every 3 months for 1 year and every 6 months thereafter. All patients received aspirin. Results: There were three perioperative strokes (one in the primary group, two in the OVP group) and no perioperative deaths. Two perioperative revisions were performed within 30 days of the original CEA for residual disease. During a mean follow-up of 59 ± 4 months, nine ipsilateral neurologic events have occurred, including two strokes and seven transient ischemic attacks. Sixteen patients had duplex evidence of recurrent stenosis, and one was associated with a stroke 36 months after CEA. Recurrence rates were similar in all groups (cumulative recurrence at 5 years: primary 7.8%, VP 14.3%, OVP 5.3%). Of the 136 patients (163 procedures), 72 (53%) (88 procedures) are alive and well, 16 (11.7%) (19 procedures) have been lost to follow-up, and 48 patients (35.3%) (56 procedures) have died. The cumulative stroke-free survival rate at 84 months was 71% for VP, 74% for OVP, and 60% for the primary group. Conclusions: These results demonstrate that CEA is a durable procedure. The use of VP closure did not produce superior long-term results compared with the use of primary closure in this select group of patients.