Objective — to determine the antihypoxic efficacy of mexidol in carotid endarterectomy (CE) procedure in patients with cerebral atherosclerotic stenosis using cerebral oximetry. Material and methods. Clinical/psycho/neurological monitoring was performed in 109 patients with internal carotid artery stenosis of 69±7.0% and neurological symptoms of cerebral ischemia, 2—3 degree, in pre- and postoperative periods. Cerebral oximetry was carried out perioperatively. Fifty-four patients were treated with mexidol in a dose of 1000 mg/day for 14—15 days and 55 patients did not received mexidol. Results and conclusion. The difference in initial brain oxygenation (rSO2) between the main and comparison groups was shown (60.8±5.0 and 47.29±5.5%, respectively). During operation, the degree of blood oxygenation in these groups decreased by 57% and 41%, respectively. On day 7, sinificant differences in the Schulte test in two groups of patients with similar neurological status were found considering efficiency of work and mental stability before and after operation. No differences were found in the comparison group. Mexidol used for antihypoxic brain protection in carotid endarterectomy of patients with cerebral atherosclerotic stenosis significantly reduces the degree of cerebral hypoxia, decreases the duration of surgery, improves neurological status of patients and performance of psychological tests in postoperative period.