Fernando, S2026-01-092025-10-10978-624-6010-15-72783 – 8862https://rda.sliit.lk/handle/123456789/4490School-Based Professional Teacher Development (SBPTD) plays a crucial role in improving instructional quality and promoting the continuous professional growth of educators. When implemented systematically, SBPTD fosters a culture of reflective practice, collaboration, and ongoing learning, ensuring that teachers consistently refine their skills to meet evolving educational needs. In Sri Lanka, despite comprehensive national-level planning and the introduction of a mandatory SBPTD handbook, schoollevel implementation has remained inconsistent, with only 8% adherence recorded within a selected Education Zone. This study investigates the reasons behind such non-compliance and proposes structured, context-responsive interventions to bridge the gap between policy and practice.encomplianceschool-based managementteacher developmentimplementation gapsSchool-Based Professional Teacher DevelopmentArticlehttps://doi.org/10.54389/DKLI8809