The results of various forms of treatment of patients with minor head injuries have been examined. The number and frequency of post-concussional sequelae was markedly reduced by treatment which included information, explanation and encouragement. Dizziness, loss of hearing and loss of balance were related to external lesions to the vestibular system caused by injuries to the parieto-temporal region of the skull. PTA proved to be a reliable indicator of the severity of cerebral concussion and correlated with post-concussional sequelae and periods of disability. Other factors which increased the number and frequency of post-traumatic sequelae, especially those related to stress before the accident, could be counteracted by better treatment of the patient. The results bear out the hypothesis that post-concussional sequelae start off on an organic basis (PTA) and that persistent sequelae after minor head injuries are also caused by psychogenic, and especially by iatrogenic factors.