Background <p>Interest is growing in whether healthcare professionals from a range of backgrounds can deliver complex behaviour-change interventions effectively. Thus, as part of a wider evaluation of ‘REDUCE,’ a novel, person-centred, cognitive behavioural intervention targeting the self-care behaviours of individuals with a history of diabetic foot ulcers, we explored whether, how, and why, a diverse group of healthcare professionals developed a sense of competence and confidence as facilitators of behaviour change. Our aim was to generate insights to support the recruitment, training, development and retention of appropriately skilled personnel for this and similar behaviour change-oriented interventions going forward.</p> Methods <p>We interviewed 15 healthcare professionals who had been appointed and trained to deliver the REDUCE intervention in the context of a randomised controlled trial. We analysed the resulting data thematically.</p> Results <p>Our interviewees described diverse backgrounds, routes into the programme, and motivations, and similarly variegated journeys towards competence and confidence as facilitators. They observed how training provided a solid foundation on which to build, but that subsequent learning – substantially self-directed – also played an important part in their development. Interviewees emphasised the particular contributions of experiential learning and reflective practice, noting the key roles that supervision and group support played in the latter, and highlighting how such arrangements helped them to learn from, rather than be derailed by, challenging cases and interactions. Finally, interviewees talked of the returns and rewards of engaging with the REDUCE programme, and how they had benefited both professionally and personally from investing in their own development as facilitators of behaviour change.</p> Conclusions <p>Healthcare professionals involved with this behaviour-change intervention were not passive recipients of training and support. Instead, they were self-directed learners who invested actively in their own development. To enable facilitators to reach their full potential, their agency needs to be recognised and interventions organised in ways which enable them to access appropriate experience and support.</p> Clinical trial number <p>Not applicable (the manuscript reports on a qualitative study).</p>