This article draws on an investigation into the extent to which teachers in one international school in Thailand had been trained for teaching in culturally diverse classrooms. It focuses on these teachers' initial and subsequent training, and probes how culturally responsive these teachers believed themselves to be. The article also considers how teachers can become more effective in culturally diverse classrooms and offers suggestions as to what international schools can do to improve teachers' knowledge of teaching a multicultural student body. Specific mention is made of Thai culture due to the author's parallel research into the impact of Thai culture on learning. (Contains 10 tables.)