An analytical framework for examining students’ motivation was developed and used for analyses of video excerpts from science classrooms. The framework was developed in an iterative process involving theories on motivation and video excerpts from a ‘motivational event’ where students worked in groups. Subsequently, the framework was used for an analysis of students’ motivation in the whole class situation. A cross-case analysis was carried out illustrating characteristics of students’ motivation dependent on the context. This research showed that students’ motivation to learn science is stimulated by a range of different factors, with autonomy, relatedness and belonging apparently being the main sources of motivation. The teacher’s combined use of questions, uptake and high level evaluation was very important for students’ learning processes and motivation, especially students’ self-efficacy. By coding and analysing video excerpts from science classrooms, we were able to demonstrate that the analytical framework helped us gain new insights into the effect of teachers’ communication and other elements on students’ motivation.