The treatment of challenging behaviour in intellectual disabilities has evolved dramatically since the 1950s, from a reliance on psychopharmacological restraint and operant conditioning to a multifaceted support plan that recognises the communicative intent of the client alongside their need for meaningful community participation. In recent years there has also been an increasing recognition of the critical role of family relationships in the maintenance and amelioration of challenging behaviour, as well as in attempts to integrate the fields of family therapy and applied behaviour analysis. The aim of this article is to describe a model of tertiary consultation that draws on the skills of systemic family therapy to assist clinicians who might be struggling with responding to challenging behaviour in settings characterised by complex and ‘stuck’ mediation problems. This model applies principles of reflective practice to assist such clinicians to develop a sophisticated understanding of the nature of interactions and relationships in the client's life, a critical prerequisite to the application of behavioural intervention. A detailed description of the model and a case study will be provided.