Direct surgical repair of complex intracranial vascular lesions is difficult. Sometimes the neurosurgery is performed under circulatory arrest, profound hypothermia and barbiturates cerebral protection. Total ischemia is tolerated for 30~60 minutes because oxygen requirements of the brain decrease exponentially as body temperature is lowered. We experienced that this technique was successfully used for inoperable basilar artery aneurysm. We reviewed the surgical and anesthetic considerations of basilar artery aneurysm.