BACKGROUND: The purpose of this study was to determine the possibility and safety of performing carotid endarterectomy under cervical plexus block. METHODS: Carotid endarterectomy was performed in 30 cases with deep and superficial cervical plexus block, to monitor the patient for cerebral ischemia in the awake state. The toy horn was placed in the contralateral hand in each case and was activated by the patient on command and patients had counted ten repeatedly during carotid clamping. Patients who had not been experienced in the change of mental status or motor response had been operated without a shunt. RESULTS: Cerebral ischemia requiring shunt was observed in one case (3.3%). There were no permanent neurologic deficit and major cardiovascular complication and mortality. CONCLUSIONS: Carotid endarterectomy under cervical plexus block allows direct and precise observation of the patient's central nervous system function during the operation.