This book explores the interplay between English for specific purposes (ESP) and English-medium instruction (EMI), the complementary ways in which EMI and ESP are implemented in different contexts, as well as teaching and assessing challenges. Furthermore, it considers teaching practices used by ESP professionals and the kind of support given to EMI through ESP. The book makes a valuable contribution to the growing body of research around EMI and ESP by offering a combined study of the presence, practices, roles and impact of English in EMI and ESP in internationalised universities. Looking at the interplay between these two types of instruction, this volume provides an opportunity for researchers and practitioners to explore how universities can (1) benefit from ESP and EMI to enhance international skills among lecturers and students in an inclusive way, (2) examine the impact of ESP and EMI on the internationalisation of Higher Education institutions, and (3) assess the outcomes that result from institutionally bundling ESP and EMI as complementary internationalisation actions in a sustainable manner.