Sixteen adolescent sexual offenders were randomly assigned to either MST or IT conditions. Youths in the MST and IT conditions received an average of 37 hours and 45 hours of treatment, respectively. Recidivism data were collected on all subjects at an approximately 3-year follow-up. Between-groups comparisons showed that significantly fewer subjects in the MST condition had been rearrested for sexual crimes and that the frequency of sexual rearrests was significantly lower in the MST condition than in the IT condition. The relative efficacy of MST was attributed to its emphasis on changing behavior and interpersonal relations within the offender's natural environment. 1 table and 28 references. (Author abstract)