Most clinicians who treat adult sex offenders utilize group therapy. However, facilitation of groups for sex offenders is often highly idiosyncratic, with great variance in the content and process of groups, clinicians’ views of intervention goals, strategies, and technique, and how the cultural fabric of the group is established. Moreover, clinicians who treat sex offenders typically have expertise in the assessment of risk, relapse prevention, and individual factors that impact the nature and magnitude of aberrant sexual beliefs and tendencies, yet have never had or don’t readily recall advanced training in group psychotherapy. To address this issue, this presentation will describe and delineate transtheoretical factors of group psychotherapy, including here-and-now processing, vicarious learning, group-as-a-whole phenomena, and developmental dynamics across the evolution of the group. Attention will be devoted to the relevance of these factors for adult male sex offender groups, with clinical case material used to illustrate significant themes. Additionally, empirically-based measures that assess group process factors showcased in this talk will be introduced. Attendees will leave this presentation with a greater repertoire of intervention strategies from which to draw, and a theoretical framework for understanding the common events and dynamics that emerge in groups for adult male sex offenders.