Background <p>Tuberculosis (TB) is a significant global health threat, particularly in high-burden countries like Pakistan. The incidence of diabetes mellitus among TB patients is rising and this bidirectional relationship between TB and DM not only increases disease burden but also complicates diagnosis, management, and outcomes. While the World Health Organization and International Union Against Tuberculosis and Lung Disease has called for integrated care models, the implementation of such strategies and integrated TB diabetes care in Pakistan’s health systems remains inconsistent and challenged.</p> Methods <p>This protocol outlines a planned mixed-methods study designed to examine the implementation determinants of an integrated TB–diabetes care package within Pakistan’s Provincial TB Control Program. The study guided by the Consolidated Framework for Implementation Research (CFIR), will focus on both inner-setting determinants (organizational structures, resources, and readiness) and outer-setting determinants (policy, inter-organizational networks, and external influences). Quantitative and qualitative data will be collected from stakeholders, including policymakers, healthcare providers, and TB site staff.</p> Analysis <p>Quantitative and qualitative data will be analysed using statistical and thematic approaches, respectively, guided by CFIR, to identify implementation determinants. Qualitative findings will be transformed into quantitative ratings to assess both the direction (barrier vs. facilitator) and the relative strength of influence of each determinant. Scores ranging from − 2 to + 2 will indicate whether a determinant exerts a negative or positive influence and the magnitude of its influence on implementation outcomes.</p> Ethical implications and dissemination <p>The study has received ethical approval from the Ethics Review Committee of Khyber Medical University. Study findings will be submitted for publication in peer-reviewed journals and will be presented at relevant conferences.</p>