A number of studies have examined HIV risk behaviors in prisoner populations, but relatively few have examined such behaviors in probationer populations. Since probationers have more opportunities to engage in risk behaviors than do prisoners, the potential importance of HIV interventions with probationers becomes readily apparent. This article examines a sample representative of the supervised probationer population in Delaware. The sample respondents received a baseline interview, then were randomly selected to receive either an enhanced version of NIDA standard HIV Intervention or a Focused Intervention based on a cognitive thought-mapping model. Intervention boosters were offered at two follow-up intervals in the following three months, and respondents were reinterviewed at six months. The data at baseline suggest that probationers in Delaware have levels of injection drug use, other serious drug use, and rates of risky sexual behaviors that approach those observed in prison populations. The interventions' effectiveness in changing attitudes and behaviors at the six-month interview was then examined. The data support the conclusion that brief interventions can significantly impact both drug use and sexual risk behaviors among probationers. However, there do not appear to be significant improvements for those receiving the more intensive Focused Intervention, as compared to those who receive the enhanced Standard Intervention. Further work will consider what components in programs and characteristics in clients should be considered in selecting the most appropriate interventions for probationers.