The need to support people to change diet-related behaviour is widely advocated and how to do this effectively in practice is an expanding area of research. Important factors to consider are how healthcare practitioners communicate with their patients and how that communication may affect diet-related behaviour change and subsequent outcomes. The aim of the present paper is to discuss communication skills for behaviour change (CSBC), focusing predominantly on registered dietitians who are required to communicate effectively and have an important role in supporting patients to change diet-related behaviour. The views of dietitians in relation to CSBC have been investigated and respondents have consistently reported that they perceive these skills to be of vital importance in practice. Patient views have reiterated the importance of good CSBC in one-to-one consultations. However, pre-qualification training of dietitians is thought to deliver practitioners who are competent at a minimum level. The need for ongoing continuous professional development (CPD) in relation to CSBC has been recognised but currently most CPD focuses on updating knowledge rather than improving these essential skills. Measuring CSBC in a consistent and objective manner is difficult and an assessment tool, DIET-COMMS, has been developed and validated for this purpose. DIET-COMMS can be used to support CSBC development, but concerns about logistical challenges and acceptability of implementing this in practice have been raised. Although a suitable assessment tool now exists there is a need to develop ways to facilitate assessment of CSBC in practice.