This action research project considered whether significant improvements in child and young person behavioural and emotional mental health could be achieved using school-based play workers as opposed to qualified therapists. This was seen as being an important practice question as access to qualified play therapists was severely restricted with long waiting lists. The Strengths and Difficulties Questionnaire (SDQ) was used as a pre- and post-intervention measure to identify any changes following non-directive play sessions with school staff. Significant improvements were found across all SDQ scales, with the most marked improvement observable in children and young people identified as having a high need for intervention. Number of play sessions attended and age group did not significantly affect SDQ scores according to teacher and child/young person ratings. Parent SDQ ratings indicated greater success of the play intervention for children aged between three and eight years compared with children aged between 11 and 15 years.