Research suggests motivational interviewing (MI) techniques are both widely-used by educational psychologists (EPs) and effective in supporting young people of secondary age. To date, there has been no published research investigating the use of MI with primary-aged children. In this study, one primary-aged pupil identified as disengaged took part in a short MI-based intervention. A case-based approach was employed, using pupil and teacher interviews, and observational fieldnotes to assess the usefulness of the intervention. Data were analysed using thematic analysis and the intervention checked for adherence to the MI spirit and principles. Here the process, structure and outcomes of the intervention are exemplified through an illustrative case study with a nine-year-old boy. Results indicate that the adapted intervention had a significant impact on learning motivation and classroom behaviour. The implications of the findings are discussed in relation to the use of school-based therapeutic interventions by educational psychologists.