The purpose of this paper is to present a potentially useful interview template for longitudinal, qualitative ESL motivation research. For this purpose, I recruited 10 Korean ESL learners in Toronto, Canada to investigate the differential effects of three types of interviews (i.e., open-ended, semi-structured, and structured interviews) for eliciting learners’ comments on ESL learning motivation. Each participant was interviewed two or three times over four months. The interviews were audio-taped and transcribed. Thematic analyses based on Ratner’s (2002) meaning unit indicated that for initial exploratory purposes, open-ended formats are the most appropriate; whereas for subsequent investigations, semi-structured formats are the most effective. The beneficial washback experienced as a result of the interviews strongly supports the use of these methods, not only as research tools but as learning tools for enhancing learners’ metacognitive awareness of their own ESL learning and for their emotional stabilization.