Reshaping substance misuse treatment in prisons is central to the UK Government’s drive to address substance dependence in the prison population and reduce substance-related offending and recidivism. Therefore, a through-care project to support prisoners released from custody to community, ‘Gateways’, is taking place across North-West England. Amongst support with housing, education, training and employment, Gateways incorporates the Breaking Free Online (BFO) substance misuse treatment programme. Aims: To explore BFO’s potential to provide support to prisoners’ substance misuse recovery and continuity of care post-release, and examine quantitative outcomes provided by prisoners who have used the programme. Methods: Qualitative interviews with prisoners and analyses of quantitative data collected pre and post intervention. Results: Themes emerging from qualitative data around prisoners’ experiences of engaging with BFO illustrate its potential for use in prison settings. Significant improvements to quality of life, severity of substance dependence and aspects of recovery progression illustrate initial effectiveness of BFO and prisoner’s intentions to continue engaging following release to the community. Conclusions: The BFO programme demonstrates potential in providing effective treatment for offenders with substance misuse difficulties, and specifically in delivering continuity of care following release to the community.