The illumination and magnification provided by the operating microscope allow for the accurate and complete removal of atherosclerotic plaque from the carotid arterial wall, for precise arterial repair at the distal end of the internal carotid endarterectomy, and for a fine, nonstenosing arteriotomy closure. A high dissection of the internal carotid artery, allowing arterial exposure above the plaque, is particularly helpful in the performance of carotid microendarterectomy. The technique of carotid microendarterectomy has been used in a consecutive series of 60 patients with symptomatic carotid stenosis, all but 5 of whom had carotid stenoses of 70% or more. In this series, there were no deaths and only one postoperative stroke, due to occlusion at the operative site. Emergency thrombectomy and angioplasty restored blood flow, and the patient recovered. In this and all other patients, carotid patency after surgery has been confirmed (angiography in 6 and Doppler examination in 54). Although postoperative stroke risk is dependent upon many factors, we feel that the refinements afforded by the operating microscope help reduce the risks associated with surgical technique to a minimum.