"Interest" is a widely used term not only in language education but also in our everyday life. However, very little attempt has been made to investigate the nature of "interest" in language teaching and learning. This paper, using a definition of interest proposed in the field of educational psychology, reports on the findings of a study conducted with a group of postgraduate students studying in an English language teacher education programme at a New Zealand university. The study uses a checklist as a tool for real-time measurement of student interest during four lectures observed. The findings suggest that there are various situational and individual sources of interest that can be exploited. The topic and content of lectures seem to play a significant role in triggering student interest. Interest in the topic can be triggered not only by what the lecturer does (situational factors) but also by what the student him/herself does (individual factors). Students themselves can be trained to seek a connection between the lecture topics, their teaching/learning experience and other subjects. Students can also come to the lecture prepared with their own personal goals and questions they would like to have addressed. (Contains 6 tables.)