• Eighty-four patients under the age of 40 were rehabilitated after severe head injuries. All had been unconscious for at least 24 hours, and 35 were unconscious for more than four weeks. The mean length of treatment was 30.2 weeks. Seventy were discharged home, 13 remained in hospital, and one died. Seventy-two of the patients were followed up nine months to 15 years after the injury. Twenty-eight were working, 27 were at home but not working, 13 were in hospital, and four were dead. Prolonged unconsciousness, extensive neurological damage, and severe mental changes were found to be the main factors adversely affecting the prognosis; an inadequate family background and cerebral hypoxia were also considered to have an influence.