One of the emerging findings in offender rehabilitation is that treatment completion and therapeutic gains can be maximised under conditions where the participant is “ready” for psychotherapeutic intervention. This study investigated the preliminary effectiveness of a Preparatory Programme designed to motivate or prepare sex offenders for treatment. The treatment targets of readiness, hope, self-efficacy, and motivation to change were measured before and after the programme. The Preparatory group showed significant positive changes on self-efficacy and hope. In contrast, sex offenders who completed a psycho-educational programme or who were on a waitlist did not receive such gains. There were no significant increases in measures of motivation however the majority of offenders subsequently commenced a full treatment programme.