Circles of Support & Accountability (COSA) started 15 years ago in Ontario, Canada, as an alternate means of social support to high-risk sexual offenders released at the end of their sentences without any community supervision. The pilot project in South-Central Ontario has since assisted almost 200 offenders. Projects based on this model are now in place in the United Kingdom, several jurisdictions in the United States, and throughout Canada. Initial research into the efficacy of the COSA pilot project showed that participation reduced sexual recidivism by 70% or more in comparison with both matched controls and actuarial norms. The current study sought to replicate these findings using an independent Canadian national sample. A total of 44 high-risk sexual offenders, released at sentence completion and involved in COSA across Canada, were matched to a group of 44 similar offenders not involved in COSA. The average follow-up time was 35 months. Recidivism was defined as having a charge or conviction for a new offense. Results show that offenders in COSA had an 83% reduction in sexual recidivism, a 73% reduction in all types of violent recidivism, and an overall reduction of 71% in all types of recidivism in comparison to the matched offenders. These findings suggest that participation in COSA is not site-specific and provide further evidence for the position that trained and guided community volunteers can and do assist in markedly improving offenders’ chances for successful reintegration.