IntroductionEmotional problems are leading contributors to health burden among adolescents worldwide. There is an urgent need for evidence-based psychological interventions for young people. This study aims to evaluate the effectiveness of a school-based, group psychological intervention, Early Adolescent Skills for Emotions (EASE) developed by the WHO to improve psychosocial distress in Pakistani adolescents.Method and analysisA two-arm, single-blinded, cluster randomised controlled trial, with a wait-list control arm is being conducted in school settings of rural Pakistan. Forty eligible public-school clusters have been randomised (stratified by gender) on a 1:1 allocation ratio into intervention (n=20) and control arm (n=20). Following informed consent, 564 adolescents with psychosocial distress (Youth-reported Paediatric Symptoms Checklist, cut-off ≥28) from 40 schools have been enrolled into the trial (14±3 average cluster size) between 2 November 2021 and 30th November 2021. Participants in the intervention arm will receive EASE in 7-weekly adolescents and 3-biweekly caregivers group sessions in schools. The adolescent sessions involve the components of psychoeducation, stress management, behavioural activation, problem-solving and relapse prevention. Caregivers will receive training to learn and implement active listening; spending quality time and using praise as a strategy to help their children. The primary outcome is reduction in psychosocial distress at 3 months postintervention. Secondary outcomes include symptoms of depression and anxiety, caregiver–adolescent relationship and caregivers’ well-being. Outcomes will be assessed at baseline, immediate 1 week and 3-months postintervention. Qualitative process evaluation will explore barriers and facilitators to programme implementation in low-resource school settings.EthicsEthics approval has been obtained from Central Ethics Committee of University of Liverpool, UK, Ethics Review Committee of WHO Geneva and from the Institutional Review Board of Human Development Research Foundation (HDRF), Pakistan.DisseminationThe findings of the study will be disseminated by WHO and through peer-reviewed publications.Trial registration numberISRCTN17755448.