This book explores issues of teaching science, technology, engineering and math (STEM) through the medium of English in the context of higher education in Hong Kong. It analyses policy issues and language challenges faced by university students and pedagogical strategies for the professional development of English-Medium of Instruction (EMI) teachers. Hong Kong as a focus case is valuable because nearly 60% of government-funded university programmes are STEM or science-related, while over 90% of the student population speaks Chinese as a first language but also speak and write English due to local language policies and Hong Kong's colonial history, making it a useful site for EMI research. By providing an evidence-based, pedagogically-focused analysis of teacher and student classroom practices and their perceptions, this book sheds light on ways to improve the quality of instructional practices and effective scaffolding in different types of EMI classrooms in Hong Kong and in similar contexts around the world. The examples of the EMI lessons with annotated notes which showcase good practices of EMI teaching will be particularly valuable to university EMI co-ordinators, content-subject and English teachers, and instructors doing EMI professional development courses.