Over the past 40 years, William Marshall & colleagues have developed & refined a motivational, strength-based approach emphasizing warmth, empathy, & 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 programs in both prison & community settings consistently achieve a broad range of treatment targets & reduce recidivism for both sexual & nonsexual crimes. The first five chapters review research & theory on sexual offender treatment, including assessment, procedural factors, personal & interpersonal factors (such as therapist features, therapeutic alliance, & group climate), problems with common cognitive-behavioral approaches, & evaluation of treatment programs. The last 3 chapters describe 3 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 reoffense (problems with attitudes and cognitions, self-regulation, relationships, & sexual issues); & the Deniers' Program, which targets criminogenic factors but is tailored to needs of those who deny committing a sexual crime.