This book showcases a range of professional development activities in English medium instruction (EMI) from diverse international contexts. While EMI offers many benefits, it also comes with challenges for both teachers and learners, especially in terms of language proficiency, teaching practices, and curriculum design. To address these challenges, professional development activities are essential for supporting teachers and learners in EMI contexts. The scope of the book includes topics such as teacher training, curriculum design, assessment, classroom practices, and policy implementation in a range of EMI settings, including higher education, schools, and vocational institutions. The book offers practical guidance and innovative approaches for practitioners that will enhance their teaching practices and support their learners. The book also provides new insights into the challenges and opportunities of EMI in different contexts and contributes to the development of new theoretical frameworks for understanding EMI. This book is intended for EMI teachers, teacher trainers, researchers, policymakers, and administrators at different levels of education.