This study investigated the development of physics student teachers’ technological pedagogical content knowledge (TPCK). Video recordings were made of four student-teachers’ classroom practices, focused on their pedagogical use of ICT in physics lessons. Following content analysis, these were then used with student teachers as prompt material for reflection on their own and others’ practice. Supplementary data was also gathered from a small-scale survey of physics student. Survey findings revealed that most of the student teachers began with limited technical ICT skills (technical knowledge) but developed these skills as the course progressed. Content analysis of the video-recorded observations showed that they had integrated ICT tools into their teaching practice, including presentation software, Internet, simulations and movie-maker. Lesson content was presented through these tools, using different pedagogical approaches including predict-observe-explain, discussions, exposition, and student-centric activities. However the student-teachers showed insufficient classroom management and organization skills (pedagogical knowledge). After viewing the video recordings, students demonstrated the capacity to reflect on the strengths and weaknesses of their practice and to explore improvement strategies. This process of reflection contributed to the development of transformative uses of technology through new pedagogical practices (TPCK). The implications of such processes for developments in ICT-mediated teacher education are discussed.