Patients undergoing carotid endarterectomy in the presence of occlusion of the contralateral carotid artery appear at greater risk for operative-related stroke or death. We had experience with 37 such patients in a five-year period. Routine intraluminal shunting without EEG monitoring was used in nine patients. Twenty-eight patients had continuous EEG monitoring during surgery. Of this group, 12 patients required intraluminal shunting based on intraoperative EEG criteria. In the early postoperative period, there was one death, and there were no instances of new, fixed neurological deficits. Life table analysis shows that 80% of the patients are neurologically stable in the five-year follow-up period. Electroencephalographic monitoring proved valuable in the detection of patients requiring intraluminal shunting, in the occasional recognition of poorly functioning shunts, and in the determination of the importance of alterations in blood pressure or cardiac rhythm on cerebral blood flow.