The clinical, criminological and demographic characteristics of a Special Hospital population of male patients convicted of homicide are described. The results confirm much previous work on mentally abnormal homicide. Typically the patients come from a disadvantaged social background with poor employment records, a prior history of aggressive behaviour and a diagnosis of schizophrenia. Victims were usually known to the patient and often came from within his circle of family and friends. Only 25% of the patients were receiving treatment at the time of the offence. These findings are discussed in the light of the current literature.