--- - |2+ Background Whole school approaches to mental health are recommended where schools and community partners work together to support positive mental health for young people. Universal interventions which adopt this approach are limited however. This study evaluates the pilot implementation of DBT STEPS‐A, a social–emotional learning programme for adolescents, in Ireland. Method Data were collected at the beginning and end of the academic year from students who participated in DBT STEPS‐A and a control group. A matched comparison was conducted where a subset of the data was analysed consisting of 72 adolescents aged 15–16 years from two schools in the south of Ireland. Outcomes included emotion symptoms, dysfunctional coping and DBT skill use. Linear mixed‐effects models were used to estimate the treatment effect (intervention vs. control). Results A statistically significant treatment effect was observed on two of four outcome measures (emotion symptom index: p = 0.011; internalising problems: p = 0.012). The effect sizes were large (Cohen's F squared = 0.65 and 0.83 respectively). Conclusions Significant reductions on measures which assess constructs including depression, anxiety and social stress were found for the intervention group. The results suggest that DBT STEPS‐A may yield positive effects for adolescents who complete the intervention. Feedback from adolescents and teachers suggests that refinement of content, structure and implementation may make the programme more accessible to an adolescent population. - Child and Adolescent Mental Health, Volume 23, Issue 4, Page 376-380, November 2018.