This article considers the use of non-directive play therapy as an approach to assessing children and young people in the care system, focusing on expert assessments in court proceedings. It uses an account of sessions of non-directive play therapy undertaken with a nine-year-old boy to illustrate the way in which this method can provide clear indications of a child’s developmental status, wishes and feelings, as well as facilitating therapeutic change. The approach is compared with other approaches to clinical interviewing, particularly those involving a series of interviews, and to assessments using psychometric testing. Finally, while arguing for the advantages of the approach, the article considers some inherent dilemmas, which arise from the fact that the child’s communications are largely within the metaphor of play. Issues of clarifying and interpreting the play may be of greater importance than if the child has made direct verbal statements, although other approaches such as psychometric testing may carry similar dilemmas.