This paper highlights the appeal of dynamic assessment (DA) for speech and language therapists (SLTs), and describes the usefulness of various DA models and methods. It describes the background to DA, and the uses to which DA has been put, by educational psychologists in the UK, and by SLTs in the USA. The research and development of methods of DA are described, and the case for developing DA methods for use in a) research and predictive applications, and b) clinical applications to inform interventions by SLTs and in collaborative practice, is made. Implications for future research are presented.