The current article presents a study of an experimental training methodology for promoting lesson analysis skills in student teachers. This methodology is based on the idea that the quality of lesson analysis skills depends mainly on teachers' perception of relevant instructional events and on their understanding of these events. The experimental intervention consists of student teachers' participation in sessions on guided analysis of videotaped lessons and writing lesson analysis reports. Gagn's model of an instructional unit is used as a theoretical framework for defining a lesson and identifying its critical events.