Substance-dependent adolescents (N = 34) in a residential drug treatment facility received either a 6-session behavior skills training HIV-risk reduction intervention or standard HIV education. After the intervention, adolescents who received behavior skills training exhibited increased knowledge about HIV-AIDS, more favorable attitudes toward prevention and condom use, more internal locus of control, increased self-efficacy, increased recognition of HIV risk and decreases in high-risk sexual activity. Self-report data were corroborated by records for the treatment of sexually transmitted diseases. The results from this pilot demonstration effort suggest that skills training based on cognitive-behavioral principles may be effective in lowering high-risk adolescents' vulnerability to HIV infection and warrant evaluation in a controlled comparison with a larger sample.