This paper describes the current challenges facing nurses and other professionals who care for people with profound and multiple intellectual disabilities. This particularly vulnerable group of service users often rely on a repertoire of non-verbal behaviours to communicate their needs and wishes. These challenges include the requirements of Person Centred Planning, the Mental Capacity Act 2005 and the evidence-based practice movement. Drawing on nursing and some other relevant professional literature, this paper explores the latter in particular and how it relates to the intuitive knowledge base that professionals use to interpret NVC behaviours in this ?eld. It concludes with a discussion of the dangers and limitations of this knowledge and skill base and posits a professional need to discipline its deployment by re?ective practice (re?exivity) within well-established therapeutic relationships. A theoretical example of re?ective practice is included.