The ‘Nothing Works’ and ‘What Works’ debates were central to discourse on recidivism in the 1970s and 1980s. When the outrage subsided and the research based on meta-analysis was reviewed, one simple message for practitioners emerged: some things work with some people some of the time. The challenge is to find the right intervention for the right person at the right time. As agents of change, no practitioner can afford to be a ‘one-trick pony’ but will draw from a toolkit of interventions to address the factors that contribute to offending behaviour. Programme interventions, specifically CBT-based group work programmes, are recognised as providing an appropriate and structured environment in which to address pro-criminal thinking and attitudes in order to achieve reduced offending and ultimately desistance and reintegration into communities. The Probation Service Strategy 2011–2014 identified the introduction of a range of programmes to enhance and support effective practice as a key goal. The Choice and Challenge Group Programme was the Service’s first nationally approved offending behaviour programme. Developed in accordance with evidence-based principles, its central focus is to challenge negative beliefs and attitudes, promote prosocial behaviours and enhance individual capacity for problem-solving and personal growth and development. This is a narrative about its implementation.