In response to increasing problems associated with drugabusing offenders, the 1991 Texas Legislature provided a statutory foundation for the development of a comprehensive drug treatment program within the state's criminal justice system. In an effort to assess the impact of the prison-based treatment component of this legislative mandate, the Texas Commission on Alcohol and Drug Abuse funded the Institute of Behavioral Research at Texas Christian University to conduct a comprehensive prison-based treatment assessment (PTA) including studies of the In-prison Therapeutic Community (ITC) treatment process and posttreabnent outcomes. This article provides an overview of the research project and findings from the 6-month follow-up study. Preprison and during-treaiment information was collected from 293 ITC program pahcipants. Six-month follow-up interviews were completed with 222 ITC program graduates and compared with a comparison Downloaded by [Ecole Hautes Etudes Commer-Montreal] at 06:18 17 August 2015 76 JOURNAL OF OFFENDER REHABILITATION sample of 75 parolees who were eligible but not sent to ITC treatment.Results showed that 80% of the inmates referred to the ITC during this study graduated, and that program graduates demonstrated marked reductions in their criminal and drug use activity from the 6 months before entering prison to the 6 months after leaving prison. Finally, ITC graduatespahcularly those who completed the fmt phase of their aftercare progmmhd lower relapse and recidivism rates in the 6 months after prison than did the parolees in comparison sample. They also reported highly favorable opinions about both the program and the counselors. Implications of these fmdings are discussed, and longer term follow-up evaluations are in progress. [Article copies awilable for a /ee fmm The H m r i h Document Delivety Service: 1-800-342-9678. E-mail dm: g e t i~i r i h s o m ]