A total of 80 officers were randomly assigned to either training or a no training condition. The probation officers then recruited 143 probationers and audiotaped their sessions at the beginning of supervision, 3 months later, and 6 months later. The audiotapes were coded with respect to the officers' adherence to the RNR model. The experimental probation officers demonstrated significantly better adherence to the RNR principles, with more frequent use of cognitive-behavioral techniques to address the procriminal attitudes of their clients. Finally, the analysis of recidivism rates favored the clients of the trained officers. The findings suggest that training in the evidence-based principles of the RNR model can have an important impact on the behavior of probation officers and their clients. (Published Abstract)