The county jail, a moderate-sized facility with 150 to 250 inmates, offers both inpatient and outpatient treatment. Services are provided in six areas: crisis management, treatment of the psychotic offender, substance abuse counseling, Graduate Equivalency Diploma preparation and testing, vocational counseling, and postrelease counseling and referral. Treatment is provided by part-time personnel: a mental health therapist and coordinator, an educator and vocational counselor, a drug counselor, an alcohol counselor, and a psychiatrist. Emergency psychiatric consultations are available around-the-clock through a community mental health center. Clients are referred to the treatment program by medical and custody staff persons, community agencies, private professionals, families, and self-referral. Clients are admitted to one or more of the program's treatment areas on a voluntary basis; their continuance in treatment is based on motivation and progress. To determine the program's success in reducing recidivism, criminal files from the San Luis Obispo County Sheriff's Department were analyzed to compare reoffense rates of 82 offenders who participated in treatment and 96 who did not. Results reveal that reoffense was significantly more prevalent (55 percent) in the control group than in the experimental group (21 percent). The multiagency treatment modality is determined to successfully address the needs of the offender population in a county jail. One table and 11 references are included.