The paper describes the establishment and first four years of operation of Thames Valley Circles of Support and Accountability (TVCOSA), an organisation which recruits and trains public volunteers into support groups for sex offenders released from prison back into the community. The paper examines the literature around the evaluation of sex offender treatment methods and discusses the problems in demonstrating the effectiveness of interventions in this area of criminal justice. Due to low numbers involved in the intervention at the point of study (14) a qualitative approach is used and the focus of the paper is on analysing incidents of recidivism (e.g. any further instance of offenceconnected behaviour) displayed in the men accommodated by the programme and subsequent actions taken by TVCOSA and other Public Protection Agencies to manage risk. Thus far none of the sex offenders involved has been reconvicted for a sexual offence. An account is given of the rehabilitation undertaken with each sex offender undergoing the programme and some key statistics relating to the group are summarised. The paper concludes with some detailed proposals for further evaluation of the TVCOSA initiative.