Background <p>Adolescent tobacco use remains a significant public health concern in low- and middle-income countries (LMICs) such as Bangladesh. To address this issue, an Intervention for Adolescent Tobacco Initiation Prevention (IATIP) has been developed. This study aims to assess the feasibility of implementing the IATIP and to evaluate its potential efficacy in preventing tobacco initiation and promoting adolescent health and well-being.</p> Methods <p>This pilot school-based cluster randomised controlled trial will be conducted among adolescents (<i>N&#xa0;</i>≈&#xa0;1280 participants) in school years 8 and 9 attending participating schools (<i>K</i> = 8 schools) in Dhaka, Bangladesh. The intervention consists of three 40-min sessions delivered over three successive days, incorporating knowledge- and skill-based lectures, interactive activities, and materials targeting tobacco prevention and health promotion. The intervention was developed based on evidence from a systematic review, a quantitative survey, qualitative focus groups, and expert consensus. The primary outcome is intervention feasibility, assessed through recruitment and attrition rates, fidelity of delivery, and acceptability. Secondary outcomes include changes in tobacco use intentions, tobacco-related knowledge, attitudes and beliefs, skills development, and measures of health and well-being. Data will be collected through structured questionnaires at baseline and at 1-month follow-up. A post-intervention process evaluation will be conducted with a sub-sample of pupils in the intervention arm and their teachers, using a mixed-methods approach to explore implementation processes, facilitation, participant experiences, and areas for improvement.</p> Discussion <p>This pilot trial addresses a critical gap in adolescent tobacco control in LMICs. By combining evidence-based strategies, the IATIP aims to equip adolescents with the knowledge and skills necessary to resist tobacco initiation and to enhance overall health and well-being. Successful implementation of the intervention may contribute to reduced tobacco initiation, lower exposure to second-hand smoke, and improved adolescent health outcomes. Given the scalability of school-based interventions, the findings of this study may inform future large-scale definitive trials and influence national policies and strategies.</p> Trial registration <p>ClinicalTrials.gov (NCT06399588)</p>