In a six- to 12-year follow-up study of 500 psychiatric outpatients, death from natural causes occurred 11/2 times the expected rate, although the excess was not significant. Death from unnatural causes occurred 31/2 times the expected rate, a significant elevation. Suicide and homicide rates were particularly excessive. Unnatural mortality was excessive among younger, but not older, patients, and among all sex-race groups except black women, none of whom died unnaturally. Initial psychiatric diagnoses highly predictive of unnatural death included alcoholism, antisocial personality, drug addiction, and homosexuality. Secondary affective disorder was predictive of excess unnatural mortality, but in all cases of such death one of the four disorders associated with excess mortality antedated the affective disturbance. No patient with an index diagnosis of primary affective disorder died of an unnatural cause. Despite a frequent history of suicide attempts, hysteria was not associated with excess unnatural mortality.