Although some psychotherapists have adopted aspects of mentoring in their style of therapy, there is little research on behavior change resulting from effective mentoring relationships. To investigate and evaluate the extent to which psychotherapists use mentoring and judge it to be effective with young adult clients, 110 psychotherapists and 90 clients were surveyed using the mentoring factor questionnaire. Results showed psychotherapists viewed mentoring as occasionally effective and ranked caring and teaching as the most effective mentoring behaviors. The client survey showed similar results. Younger psychotherapists of a behavioral orientation used mentoring significantly more than older, more experienced psychotherapists of a Rogerian or psychoanalytic orientation. Female therapists used caring more effectively, while males used guiding, advising and sponsoring more effectively. Clients judged mentoring to be more effective in the treatment of persons seeking personal development and growth, but significantly ineffective in the treatment of sexual, marital or relationship problems. The results suggest that mentoring can be a viable therapeutic approach when judiciously applied. (JAC)