While most sexual offender treatment programs take an aggressive, confrontational approach that targets the offenders' denial, research has shown that this common approach does not alter actual criminogenic factors related to reoffence rate. Furthermore, this approach can alienate and demoralise offenders, who often report "not getting anything out of it." Over the past 40 years, William Marshall and colleagues have developed and refined a motivational, strength-based approach emphasising warmth, empathy, and support for the offenders. Backed by research, this positive approach does not ignore criminogenic factors, but presents them to clients as targets for the development of strengths rather than as deficits to be overcome. The approach has paid off: such programmes in both prison and community settings consistently achieve a broad range of treatment targets and reduce recidivism for both sexual and nonsexual crimes. This book presents the evolution and distinctive features of Marshall's positive approach to treating sexual offenders. The first five chapters review research and theory on sexual offender treatment, including assessment, procedural factors, personal and interpersonal factors (such as therapist features, therapeutic alliance, and group climate), problems with common cognitive-behavioural approaches, and evaluation of treatment programmes. The last three chapters describe three treatment programs developed by Marshall and colleagues for the Canadian prison system: the Preparatory Program, which engages sexual offenders in the process of change before the main treatment program begins; the Primary Program, which targets criminogenic factors that are known to predict reoffence (problems with attitudes and cognitions, self-regulation, relationships, and sexual issues); and the Deniers' Program, which also targets criminogenic factors but is tailored to the specific needs of those who deny committing a sexual offence. This landmark volume will challenge how sexual offender treatment is typically conducted. It is essential reading for psychologists, psychiatrists, social workers, counsellors, and parole and probation officers working with sexual offenders.