In the past decade, researchers have argued for translanguaging as an instructional and epistemological approach that forwards to educators the idea that multilingualism is an asset. Teacher education programs play a pivotal role in preparing teachers who enact this vision. Yet, research on teachers’ receptivity to translanguaging’s (re)orientation towards mainstreaming multilingualism remains scarce. To redress this gap, this study investigated one cohort of mainstream preservice teachers’ uptake of translanguaging theories during an online ESOL methods course required for TESOL certification. Through the analysis of interview data and participants’ written reflections and coursework, we explored preservice teachers’ beliefs and the evolution of their views on language learning, language, linguistic diversity, and translanguaging for one semester. This presentation reports on the findings of this project, highlighting the challenges and potential benefits of translanguaging theories’ translation into practice.