Recent findings from a research study conducted with support from the National Institute of Justice and the National Institute on Drug Abuse suggest that intensive case management, delivered for 6 months, can reduce drug use and recidivism and increase use of substance abuse treatment among drug-involved arrestees released after booking. This study, which was based on a controlled experiment involving close to 1,400 arrestees, was conducted in Washington, D.C., and Portland, Oregon. Case management also was intended to reduce sexual-and injection-related risk behaviors implicated in the transmission of human immunodeficiency virus (HIV), the causative agent of acquired immunodeficiency syndrome (AIDS). Case management was less successful in improving these specific HIV-related outcomes. However, the study suggests how further refinements to the case management model might elicit improved outcomes associated with HIV prevention.