OBJECTIVE: It has been argued that among the homeless many of the features of antisocial personality may be artifacts of homelessness and that strict application of the diagnostic criteria may be insensitive to social and cultural factors in this group. The authors studied a large group of homeless men and women to investigate the appropriateness of the diagnosis of antisocial personality disorder among the homeless. METHOD: Six hundred homeless men and 300 homeless women were randomly selected from shelters and street locations in St. Louis and interviewed with the National Institute of Mental Health Diagnostic Interview Schedule. RESULTS: In this sample of homeless men and women, most, but not all, adult symptoms of antisocial personality disorder were significantly associated with number of childhood conduct disorder symptoms. The onset of symptoms of antisocial personality disorder usually preceded the onset of homelessness. The rates of antisocial personality disorder were not significantly affected by discounting the antisocial disorder symptoms thought to be confounded with homelessness. CONCLUSIONS: Overall, the data support the appropriateness of the diagnosis of antisocial personality disorder among homeless populations. It cannot be said from these data that homelessness often leads to antisocial behaviors.