Obesity and its consequences, such as diabetes and cardiovascular disease (CVD), have significant health and NHS cost implications. Relatively small reductions in weight (around 5–10%) have clinically important benefits (Pietrzykowska, 2016), but long-term weight loss maintenance is challenging. Behaviour change interventions have been identified as key for use in weight loss by authorities such as the National Institute for Health and Care Excellence (NICE, 2014). In particular, motivational interviewing (MI) — a form of behaviour change — has been identified as a successful approach to changing health behaviours (Rollnick and Miller, 2013).There is an abundance of evidence showing that just telling people what to do does not work as a way to change patients’ behaviour in order to achieve health gains (NICE, 2014). Furthermore, there is emerging evidence that MI does work and leads to long-term health gains. This article provides an overview of MI to help general practice nurses (GPNs) in their day-to-day practice.