The aim of the research was to examine the influence of isoflurane inhalation on the circulatory dynamics, encephalic bloodstream and oxygen balance of the patients' brain during the carotid endarterectomy. 26 patients were examined. There were detected the parameters of central and systemic circulatory dynamics, the speed of the bloodstream in the middle encephalic artery in M₁, sector, the results of transcranial cerebral oxymetry. The first stages of the operation, the stage of temporary breakoff of the blood circulation in damaged artery territory were accompanied with moderate lowering of indicators of circulatory dynamics. In the process of reinitiation of the bloodstream the reperfusion of brain declared itself moderately. Isoflurane anesthesia to 1 MAK (minimum alveolar concentration) in combination with phentanyl allows to maintain appropriate pain management, stable circulatory dynamics and well-timed awakening of patients during carotid endarterectomy.