Evidence-based programs for substance use and HIV prevention (SUHIP) were adapted for high-risk juveniles detained at 24-hour secure correctional facilities. In this pilot study, comparisons were made between adolescents who received the SUHIP intervention and a control group on changes in: (1) knowledge of HIV prevention behaviors, (2) attitudes and beliefs about HIV, (3) attitudes toward condom use, (4) rates of stimulant use, and (5) self-efficacy for being drug free. Assessments were completed at baseline and two months subsequent to their release in the community. The 48 participants who completed both assessments were predominately Latino and African American, ages 14 to 19 years, and male (56%). Results revealed that the SUHIP group, relative to the control group, demonstrated: (1) greater increases in knowledge of HIV prevention behaviors, (2) decreases in erroneous beliefs regarding HIV vulnerability and testing, (3) increased ease in carrying and using condoms (4) lower stimulant use among girls, (5) increased self-efficacy in avoiding drug and alcohol use. In addition, the SUHIP group experienced greater improvements in attitudes about the school atmosphere, and greater reductions in problem behaviors, fights, and trouble with the law. Incorporation of evidence-based HIV and substance use-prevention programs in juvenile correctional facilities is feasible and can yield positive outcomes for high-risk incarcerated male and female juvenile offenders. (Contains 2 tables and 9 figures.)