The findings show that the treatment group was more likely to be charged with a probation violation; whereas controls were significantly more likely to be arrested for a criminal offense during the 18-month follow-up period. This confirms the literature's consistent finding that intensive supervision significantly increases rates of technical violations; for example, among the offenders on intensive probation supervision, treatment participants were drug tested an average of 18 times compared to a mean of 11.5 for the control group. The treatment group experienced a larger reduction in mean incarcerations compared to the control group, again suggesting a positive effect of residential drug treatment. The offenders who composed the treatment group had generally exhausted the less-intensive sanctions, such that any subsequent violations or crimes would lead to incarceration. This may also partially explain why the treatment group was more high-risk than the control group. The findings are promising and provide partial support for the hypothesis that high-risk offenders who participate in residential drug treatment will have lower rates of recidivism than a matched group of offenders who did not receive treatment. The study used a quasi-experimental research design to match 82 probationers who participated in residential drug treatment to 82 probationers with similar demographics and criminal histories who did not attend treatment. Study participants were sampled from one of seven treatment facilities in a southeastern State that provided residential drug treatment to offenders under community supervision. The programs were designated approved providers and were similar in the services they provided. Each offered residential treatment that included individual and group therapy, family counseling, psycho-education, relapse prevention, and aftercare. 3 tables, 6 notes, and 56 references