Promoting mental health and well-being for children and young people in the UK has attracted increasing prominence in recent years and has been a focus for government strategy within health and education. Training and practice in educational psychology has increasingly focused on developing skills and expertise to provide therapeutic support within school contexts, at an early stage of need. One approach, Cognitive Behaviour Therapy (CBT), has been heralded as an effective, evidence-based intervention for anxiety. This research examines the factors influencing the outcomes of a group CBT-based intervention, run by an Educational Psychologist (EP), in a school setting. The findings suggest that influential variables included pupil identification, measures of change applied and the role of school staff. It is concluded that EPs can play a key role in increasing access to psychological therapies, alongside considering due caution in relation to the application of traditional clinical approaches in school contexts.