It has become crucial for risk reduction interventions targeting injection drug users (IDUs) in treatment to be "community-friendly" and potent over time so that limited resources may be optimally utilized. This study examined (I) the extent to which observed post-intervention effects-including enhanced HIV-related knowledge, motivation, behavioral skills, and drug- and sex-risk reduction behavior-decayed over time and (2) whether repeating the intervention at follow-up provided additional benefit. Approximately 10 months after completing an adapted, substantially shortened, version of an evidence-based intervention, participants completed a follow-up assessment and then repeated the intervention. No evidence of decay was found. Even so, after repeating the intervention, a trend toward additional sex-risk reduction was observed for participants at higher risk for HIV. Findings point to the potential for an adapted evidence-based intervention for IDUs to be both community-friendly and potent over time within community-based treatment settings.