Abstract: Neuro-linguistic programming (NLP) is a popular form of inter-personal skill and communication training. Originating in the 1970s, the technique made specific claims about the ways in which individuals processed the world about them, and quickly established itself, not only as an aid to communication, but as a form of psychotherapy in its own right. Today, NLP is big business with large numbers of training courses, personal development programmes, therapeutic and educational interventions purporting to be based on the principles of NLP. This paper explores what NLP is, the evidence for it, and issues related to its use. It concludes that after three decades, there is still no credible theoretical basis for NLP, researchers having failed to establish any evidence for its efficacy that is not anecdotal.