ABSTRACT Four motivational factors were examined as predictors of treatment effectiveness for 48 male child molesters seen in outpatient therapy. Clients participated in about one year of multi-modal cogni-tive/behavioral therapy. Acceptance of the problem, attendance, prompt-ness, and level of participation in therapy sessions were used as predictors in regression analyses of two outcome variables: (1) mastery of the principles and concepts from the cognitive/behavioral therapies as measured by proficiency tests and (2) mastery of aversive conditioning procedures as measured by penile plethysmographic monitoring of sexual arousal. Results support earlier findings in the literature that client motivation is related to successful treatment outcome. Motivational factors were more predictive of mastery over cognitive/behavioral therapy approaches than of changes in sexual arousal patterns. Acceptance of responsibility for sexual deviancy consistently proved to be an effective predictor of favorable treatment outcome. Results thus appear to have important implications for handling child molesters in denial and/or who are not compliant with attendance requirements.