SUD’s are a serious public health issue among adolescents and present challenges to treatment. Despite the need for more knowledge on SUD’s in the adolescent population, little data exist. The current study estimated the 6-month prevalence of multiple SUD’s in a random sample of 1,829 male and female juvenile detainees, aged 10 to 18 years, from 3 racial/ethnic groups: African-American, White, and Hispanic. Participants completed the Diagnostic Interview Schedule for Children (DISC), which contained questions regarding the presence of DSM-III-R alcohol, marijuana, and other drug abuse and dependence. Results of statistical analyses indicated that almost half of the detainees had one or more SUD’s and more than one-fourth of detainees had two or more SUD’s. The combination of alcohol and marijuana was the most prevalent SUD; 17.25 percent of female detainees and 19.42 percent of male detainees reported using these two substances. Less than 6 percent of detainees had SUD’s that involved illicit drugs other than marijuana. Significantly more females and more Whites had combinations of SUD’s involving illicit drugs other than marijuana. These findings are consistent with previous findings of high rates of multiple SUD’s among juvenile delinquent samples. Substance use treatment should target multiple SUD’s among juvenile detainees who are likely to return to communities where no treatment services are available. Clinicians should help ensure continuity of care through partnerships with the juvenile justice system. Future research should identify effective treatment interventions. Figures, tables, references