During the past 2 decades psychiatry has made great progress in describing patterns of violence by psychiatric patients and developing standards for the evaluation and treatment of these patients. Studies have found that roughly 10% of patients were violent toward other persons just prior to psychiatric hospitalization. Young male patients and patients in certain diagnostic groups had higher rates of violence. This report describes the proper evaluation of violent patients and proposes a model for the short-term potential of violent behavior. Psychiatry has developed guidelines for the acute treatment of violent patients using verbal intervention, physical restraint, and emergency medication. Long-term treatment relies on medication for the underlying disorder. Beyond their traditional indications, carbamazepine, propranolol hydrochloride, and lithium carbonate may be effective in diminishing violence. Some violent patients respond to long-term psychotherapy.