The Center uses a modified therapeutic community approach that incorporated 12-step programming. It provides up to 6 months of primary drug treatment as an alternative to incarceration for probationers at high risk for recidivism, relapse, and technical violations. Treatment includes life skills training, drug education, and group counseling, 3 months of residential aftercare for participants without a transitional social support system, and 6 months of outpatient aftercare for all participants. The study examined arrest records with respect to participants' backgrounds and program completion. The 1-year follow-up outcomes were highly favorable for program graduates, particularly for those who entered the residential aftercare component of the treatment continuum. However, the lack of random assignment of participants prevented the determination of causal attribution. Nevertheless, findings support the need for providing treatment to probationers with drug problems and suggest the need for further outcome research. Tables, figures, note, and 6 references