Although English medium instruction (EMI) can be regarded as a recent phenomenon in most non-Anglophone countries, it currently plays a paramount role in the endeavor to internationalize university systems. The connections between content and language integrated learning (CLIL) and EMI are obvious; however, the lack of integration between language and content in EMI lectures has led most researchers in the field to prefer the label EMI when talking about tertiary education. In this chapter, we put forward a systematic review of research investigating EMI teacher education between 2010 and 2020. Our analysis reveals the need to optimize some shortcomings that are consistently identified in the literature, such as a noticeable imbalance in the existing corpus of EMI research, the lack of teacher training, or the need to promote teacher collaboration.