A pressing concern in English Medium Instruction (EMI) is the necessity for professional development (PD) programs targeting lecturers in higher education institutions. These programs aim to enhance both pedagogical skills and English language proficiency, enabling educators to effectively teach academic subjects in English. In light of this, our systematic review explores national and international research addressing PD in EMI higher education contexts. Adhering to the PRISMA 2020 guidelines, we examined 15 research articles published between 2019 and 2024. Our analysis focused on research design, context, sample, data collection instruments, findings, and implications. The majority of studies (eight) employed mixed methods, while five used qualitative approaches and two utilized quantitative methodologies. The review identified key challenges faced by EMI lecturers, including language competency and the adaptation of teaching methods. These findings underscore the importance of tailored, interactive, and ongoing professional development opportunities. Our primary conclusions suggest that effective PD initiatives should integrate both language and teaching skills, be discipline-specific, and address multilingual and multicultural educational settings. Furthermore, the review emphasizes the crucial role of institutional support and well-defined policies in enhancing PD effectiveness. The implications drawn from this study can inform the development and implementation of impactful professional development programs, ultimately improving the quality of EMI in higher education institutions.