This study examines the factors that limit intermediate-phase mathematics teachers' participation in professional development (PD) workshops within the Chris Hani East Education District, South Africa. Despite the recognized importance of PD for enhancing teaching practices and learner outcomes, participation remains low, particularly in under-resourced areas. Guided by the Theory of Planned Behaviour, the study employed a qualitative case study design, collected data through semi-structured interviews, observation, and document analysis. Findings reveal that combination barriers hinder teacher participation, including time constraints, limited institutional support, inadequate resources, and personal challenges such as financial strain and workload. In addition, concerns about the relevance and quality of PD workshops negatively influence teachers' motivation to attend. These obstacles restrict professional growth and undermine efforts to improve mathematics instruction. The study recommends targeted interventions, such as flexible scheduling, improved resource allocation, stronger leadership support, and more relevant, needs-based PD content. Addressing these issues is essential to enhancing teacher engagement in PD and improving mathematics education in the district.