This systematic literature review investigates the adoption and impact of English Medium Instruction (EMI) in Saudi Arabian higher education. It synthesizes findings from 18 empirical studies, primarily in applied sciences such as engineering, medicine, and computer science, while noting a dearth of research in social sciences. The review reveals a uniformity in student perceptions of EMI across disciplines, highlighting its widespread acceptance and challenges in cultural and linguistic adaptation. It also emphasizes the diversity of research methodologies used, offering insights into both teacher and student perspectives. This comprehensive analysis not only maps the current landscape of EMI in Saudi Arabia but also identifies critical areas for future research, particularly in understanding its long-term educational and socio-cultural implications.