BACKGROUND. This investigation sought to determine the prevalences of various psychopathologies in outstandingly creative individuals, and to test a hypothesis that the high prevalence of mental abnormalities reported in prominent living creative persons would not be found in those who had achieved and retained world status. METHOD. The family background, physical health, personality, psychosexuality and mental health of 291 famous men in science, thought, politics, and art were investigated. The membership of the six series of scientists and inventors, thinkers and scholars, statesmen and national leaders, painters and sculptors, composers, and of novelists and playwrights was determined by the availability of sufficiently adequate biographies. Extracted data were transformed into diagnoses in accordance with DSM- III-R criteria, when appropriate. RESULTS. All excelled not only by virtue of their abilities and originality, but also of their drive, perseverance, industry, and meticulousness. With a few exceptions, these men were emotionally warm, with a gift for friendship and sociability. Most had unusual personality characteristics and, in addition, minor 'neurotic' abnormalities were probably more common than in the general population. Severe personality deviations were unduly frequent only in the case of visual artists and writers. Functional psychoses were probably less frequent than psychiatric epidemiology would suggest, and they were entirely restricted to the affective varieties. Among other functional disorders, only depressive conditions, alcoholism, and, less reliably, psychosexual problems were more prevalent than expected in some professional categories, but strikingly so in writers. CONCLUSIONS. Similar findings have been reported for living artists and writers, and this suggests that certain pathological personality characteristics, as well as tendencies towards depression and alcoholism, are causally linked to some kinds of valuable creativity.