Objective: This study examines the efficacy of a six week child mindfulness program (TRIPLE R) in teaching mindfulness skills and reducing negative emotional symptoms in a school setting. Method: Using a correlational within-subjects repeated measures design, the relationships between child self-reported mindfulness skills and negative emotional symptoms were explored. Mindfulness skills were measured using the Child and Adolescent Mindfulness Measure, and emotional symptoms were measured using the Revised Children’s Anxiety and Depression Scale. A sample of 57 Australian grade 5 children in three primary schools completed the measures pre and post intervention. Results: There was a small to moderate increase in mindfulness skills post intervention (Cohen’s d = 0.32), however negative emotional symptoms did not significantly improve. Increased mindfulness skills were significantly associated with decreased emotional symptoms, most notably for symptoms related to social phobia (R = −.61), separation anxiety (R = −.42) and generalised anxiety (R = −.32). Discussion: This study provides preliminary support for the TRIPLE R program and the potential benefits of school-based mindfulness interventions in improving children’s well-being. The limited improvement in negative emotional symptoms is likely related to the non-clinical sampling. The relationship between increased mindfulness skills and decreased emotional symptoms is discussed, and recommendations for further research are presented.