The first four weeks of the program constitute the assessment phase, during which a routine battery of assessment and interviews are involved. Persons deemed unsuitable for the program after the assessment are returned to the prison system. The treatment format is intensive group therapy, which includes psychoeducation groups, interpersonal skills training, relapse prevention, and more traditional psychotherapy groups. Other forms of therapy are used as required by each individual patient. Under the current evaluation, there were 120 subjects who successfully completed the program and 100 who did not complete the program. Sexual and nonsexual offense recidivism, with an average follow-up time of 38.8 months, was used to evaluate treatment efficacy. The recidivism rates differed significantly between groups and were 3.3 percent and 10.0 percent for sexual offenses and 12.5 percent and 27 percent for nonsexual offenses, respectively, for those who completed the program and those who did not complete it. The findings suggest that comprehensive treatment of sexual offenders can substantially reduce sexual as well as nonsexual offense recidivism rates. 1 table and 10 references