This chapter reports on a participatory action research (PAR) project that sought to help three teachers of English as a foreign language (EFL) at a Vietnamese university to adopt a stronger intercultural stance in their teaching. After a preliminary phase of observations and interviews by the researcher (also a teacher at the university), the project went through two action research cycles of workshopping and lesson planning, followed by teaching, reflecting on teaching, and identifying further steps to be taken. This chapter adopts a case study approach to focus on the experience of one of the participating teachers, Mr. Sang. Data includes observations of Mr. Sang’s teaching before, during and after the project along with semi-structured and stimulated recall interviews. The study shows how Mr. Sang successfully transitioned to teaching more interculturally and was able to do so without compromising the language skills goals of the course he was teaching. The chapter highlights the importance of participatory, context-situated professional support for helping teachers adopt intercultural teaching practices.