Thirty (33%) of 90 patients with the Gilles de la Tourette syndrome exhibited self-injurious behaviour. Fourteen were head bangers, of whom two had cavum septum pellucidum. Clinical correlates of self-injury were the severity of Gilles de la Tourette syndrome symptoms and psychopathology, with special reference to obsessionality and hostility. We discuss an additional patient who died from a subdural haematoma as a result of head banging, and three who had permanent vision impairment from self inflicted eye injuries.