This case study describes the application of a human-centred design approach to encourage young men in Zambia and Zimbabwe to become circumcised. It addresses the use of research methods grounded in behavioral science to understand how men make decisions about voluntary medical male circumcision, the development of a behavioural framework to map the stages of that journey, the development and piloting of tools to enable community mobilisers to identify persuadable men and reach those men with messages designed specifically for them, the evaluation of the interventions, and guidance for future application of the approach.