Inmates were randomly selected from 25 male prisons; 1,741 of a possible 1,864 agreed to be studied. All subjects chose their own ethnic group. Prison files and medical records were examined. Each man was interviewed by a psychiatrist. Seventeen percent of men reported DSH on at least one occasion during their life (more white than nonwhite prisoners). More white men in the medium and long-term sentence group than in the short-term sentence group reported a history of DSH. White prisoners were apparently more likely to have cut themselves than black prisoners. DSH was associated with alcohol dependence but not with drug addiction. Neurotic and personality disorders were more commonly diagnosed in the DSH group. There was a weak association between criminal violence and DSH over the prisoners' lifetime. The associations with DSH suggest that this phenomenon is a symptom of long-term personality problems and cannot be simply attributed to short-term environmental stress. Such problems are perhaps more common in white prisoners than black ones. 4 tables and 14 references