How can teacher educators gauge what participants have learnt after taking a course in teaching English as a second language (TESL)? One method that can help both language teacher educators and their students trace conceptual changes as a result of taking a course is the use of concept maps. This paper examines the conceptual changes of a group of MA participants in Canada as a result of taking a TESL course. Pre-course and post-course concept maps were elicited from the participants who were also asked to write short descriptions of changes (and the reasons for these changes) they observed between their pre- and post-course maps. Participants were also interviewed about the contents of their individual concept map and their perceptions of the course. Results indicate that the course had some impact on the participants' prior beliefs and that a concept map may be a useful tool for tracing conceptual change.