A 57-year-old man was admitted to the Emergency and Critical Care Department with accidental hypothermia (31.5 degrees C) after resuscitation from cardiopulmonary arrest (CPA). Brain CT revealed an acute subdural hematoma. Active core rewarming to 33 degrees C was performed using an intravenous infusion of warm crystalloid. The patient underwent craniotomy soon after admission, with bladder temperature maintained at 33 to 34 degrees C throughout the surgery. Therapeutic hypothermia (34 degrees C) was continued for 2 days, followed by gradual rewarming. After rehabilitation, the patient was able to continue daily life with assistance. Traumatic brain injury (TBI) following CPA is associated with extremely unfavorable outcomes. Very few patients with acute subdural hematomas presenting with accidental hypothermia and CPA have been reported to recover. No suitable strategies have been clearly established for the rewarming performed following accidental hypothermia in patients with TBI. Our experience with this patient suggests that therapeutic hypothermia might improve the outcome in some patients with severe brain injury. It also appears that the method used for rewarming might play an important role in the therapy for TBI with accidental hypothermia.