The main concern of the current paper is to discuss English medium instruction (EMI, henceforth) in all aspects with a particular focus on its challenges and difficulties reported by both students and teachers based on the relevant research studies. As EMI is gaining greatest importance among the researchers, policy makers and educators; it is of crucial importance to unreveal the main instructional problems during the implementation process in order to reach a clear understanding of it. Within this purpose, an integrative research study was undertaken by selecting five major works on the issue under investigation here. Accordingly, these fundamental research studies were analyzed in order to answer the main questions in this integrative research study which attempts to provide a comprehensive picture of EMI in Turkish context. As the interpretation of the qualitative data reveals that, the EMI policy has not only instructional challenges but also language related difficulties both for students and teaching staff.