Dynamic assessment represents an opportunity for educational psychologists to utilise a play-based approach for assessing the functional behaviour of children who struggle to perform in formal testing situations (Tzuriel, 2000; Hill, 2015). A systematic literature review aims to evaluate available empirical research on the use of dynamic assessment approaches within the early years to provide a clearer view of the evidence for their use and to support educational psychologistsâ development of such approaches within their professional practice. The review of this evidence indicated mixed results for the usefulness of dynamic assessment in the early years phase and warranted closer inspection of the use of dynamic assessment by educational psychologists. In the empirical project, a purposive convenience sample was used. Two practising educational psychologists were interviewed using semi structured interview schedules and observed delivering dynamic assessment in the Early Years Foundation Stage. Interviews were analysed using thematic analysis and a content analysis was used to analyse the videoed observations. The findings of this empirical project highlight the type and level of mediation required for dynamic assessment of children in the Early Years Foundation Stage; how educational psychologists evaluate the usefulness of dynamic assessment for assessing and identifying the needs of children in the Early Years Foundation Stage; and the implications of dynamic assessment for intervention for children in the Early Years Foundation Stage. Implications are discussed for promoting the use of dynamic assessment among educational psychologists as a useful tool for assessment of children in the early years age phase.