One hundred and one civilians with acute head injuries were subjected to an intensive study of the multiple factors in the pretraumatic and posttraumatc personality status. In most patients psychological changes became more manifest about three to six weeks after discharge from the hospital. Patients with pretraumatic neurotic personalities had a greater proportion of posttraumatic psychiatric symptoms. There was no close correlation between the severity of the injury to the brain and the severity of the sequelæ. No correlations were found which would permit the ascription of psychiatric sequelæ to one particular case or group of cases.