A 48-year-old woman was scheduled for total hysterectomy under spinal anesthesia in a local hospital. Large doses of diazepam (20 mg) and pentazocine (30 mg) were administered for sedation five minutes after starting the operation. Four minutes later, cardiac arrest occurred. The patient did not respond to closed chest massage and was transferred to our institution. As closed chest massage was not effective because the patient was moderately obese and her abdomen was open, open chest massage was initiated with administration of a large dose of epinephrine. Five minutes later, cardiac rhythm was restored, but it had taken a total of 75 minutes to restore cardiac rhythm and the patient suffered brain death. The cause of cardiac arrest was suspected to be a lethal dose of sedatives under spinal anesthesia. CT revealed massive cerebral edema soon after resuscitation. Serum NSE (neuron specific enolase) was within normal limits (< 10 ng.ml-1) at that time, but on the following day the CT demonstrated low attenuation area of white matter and gray matter in the cerebrum and brainstem, and serum NSE increased to 357 ng.ml-1, indicating massive necrosis of neuronal cells. The high concentration of serum NSE persisted for four days, and subsequently decreased to 112 ng.ml-1. This may have been a sign of completion of washout after brain death with no cerebral perfusion. It was concluded that if a case of cardiac arrest does not respond to closed chest massage, immediate open chest massage should be considered and that serum NSE may be an indicator of prognosis of hypoxic cerebral injury.