EMI has become a significant educational trend (Graddol, 1997, p.45). During the last two decades, there has been a sharp rise in the number of EMI programmes implemented in Higher Education around the world (e.g. Wachter & Maiworm, 2014). This global phenomenon, however, has led to various ways of implementation in national, institutional, and classroom contexts, which can be seen in existing literature on EMI. Against this backdrop, the current case study adopts an ethnographic perspective and focuses on the EMI implementation at a university in Vietnam – where English is a foreign language and its roles have been increasingly recognised through both top-down policies and bottom-up initiatives. Data was collected in a semester from interviews, focus groups, classroom observations, and other supplementary sources of information. In this presentation, I am going to address a part of the research that investigates how the lecturer and student participants enact their EMI policy in daily classroom practice. Based on the ROADMAPPING framework (Dafouz & Smit, 2014), the findings highlight the necessity to acknowledge lecturers’ and students’ agency in the policy implementation. Playing their roles as policy actors at classroom level, they negotiate and translate the policy in their language practice