This study aims to explore a teacher educator's perceptions and practice of translanguaging in his education classrooms as a teacher of English as a medium of instruction (EMI). Adopting a qualitative case study approach, the research revealed that the teacher educator used three translanguaging strategies (i.e. integrating academic discourse with everyday discourse, linking verbal and other semiotic resources, and using students' first language) to create a 'translanguaging space' in his EMI classrooms for content teaching and learning. The findings also showed that the teacher educator's translanguaging practice was both planned and generative, depending on his situated teaching context which presented him with various teaching opportunities and challenges (e.g. students' resistance and university policy). The study highlights the importance of teacher educators' reflective practice in their execution and improvement of translanguaging practice in EMI classroom settings.