Investigations of assaults in psychiatric hospitals have found that a small proportion of inpatients are responsible for a large percentage of the violence that occurs. In a large state hospital patients who were repeatedly violent (recidivists) were compared with patients who were violent only once or twice (nonrecidivists), and the relationships between repeatedly violent behavior and gender, age, and diagnosis were examined. All reports of violent incidents over a six-month period for a population of 1,552 inpatients—a total of 497 incidents involving 313 patients—were reviewed. Seventy patients were involved in three or more incidents each and were responsible for 53 percent of all violence. Recidivist men inflicted serious injuries at a rate ten times higher than that for all the other violent patients. Recidivist women were significantly younger than nonrecidivist assaultive women and were about the same mean age as the assaultive men. Recidivist women were also more likely to have organic brain disorder or personality disorder.