This study explores how eight teachers in one-to-one environments frame, reframe and develop different aspects of their practice during a two-year long study. The data consists of 23 hours of transcribed open-ended interviews, 35 reflective log entries written by the teachers, their educational designs and the researchers’ field notes. The results show: (a) how different dimensions of the teachers’ pedagogical reasoning are formulated, manifested and developed during the time of the study and (b) how different aspects of their technological, pedagogical and content knowledge are included in and developed through their pedagogical reasoning.