A total of 148 health and social care practitioners were trained in skills to support behaviour change: creating opportunities to discuss health behaviours, using open discovery questions, listening, reflecting and goal-setting. At three time points post-training, use of the skills was evaluated and compared with use of skills by untrained practitioners. Trained practitioners demonstrated significantly greater use of these client-centred skills to support behaviour change compared to their untrained peers up to 1 year post-training. Because it uses existing services to deliver support for behaviour change, this training intervention has the potential to improve public health at relatively low cost.