In the current balance of the literature, interventions based on the principles of relapse prevention are considered to be relatively effective in reducing recidivism among child sexual offenders. Programmes of intervention featuring this approach rely on extensive client self-disclosure. However, it is widely observed that members of this population typically exhibit considerable reluctance in this respect. The engagement of these clients in effective therapy is therefore especially problematic. Conventional wisdom holds that a therapeutic group format offers the best approach to this challenge. Yet the literature in the area of sex offender treatment has tended to focus almost entirely on matters of procedure and technique, with little regard to context and process. The aim of the current study was to identify factors contributing to the engagement of men involved in a prototypical prison-based group treatment programme. A grounded theory methodology was used to explore the experience of clients undergoing one particular component of the programme: the offence-disclosure module. Data collection focused on a key session within this module, during which each client presents his pattern of offending to group members. Using an articulated thoughts technique in conjunction with material video-recorded from the session, research participants were requested to report in detail on their experiences during episodes of high personal salience. Transcripts from these reports formed the core of the data for the first phase of the study. These data support the value of the group format, but also suggest that clients adopt certain disclosure strategies, which influence therapeutic engagement. Moreover, considerable potential therapeutic value appears to be unrealised during clinical sessions themselves. Interestingly however, some of the most profitable experiences, it seems, occur outside the formal therapy group context. These experiences were explored in a second phase of the study. Four distinct disclosure orientations are described, with implications for both in-session and out-of-session engagement. The outcome of the study challenges the widespread notion that the “resistance” commonly exhibited by these clients is an intrinsic feature of those who offend sexually against children. Instead, resistance is re-framed as a feature of disclosure orientation, emerging as a dynamic relational element in response to the challenges of therapy. As such, it appears to be amenable to therapeutic intervention.