Set against a background of societal pressure and preference for English language education in Hong Kong, this paper explores the policy and practice of English medium instruction (EMI) from the perspective of one group of content subject teachers. Grounded in Bakhtin's dialogism, the paper reports the results of a qualitative study that used in-depth interviews to explore the perspectives and experiences of these teachers as they implement EMI policy in Hong Kong schools. The results reveal the existence of several discourses of EMI in Hong Kong that position the teachers at community, institutional, and professional levels. The results also suggest that the interplay of EMI discourses can offer content subject teachers positions which they regard as undesirable. Suggestions for ensuring that the voices of these teachers are heard within the context of teacher professional development opportunities in EMI settings are considered and implications for future research are discussed. Copyright © 2022 John Benjamins Publishing Company.