This study intends to explore student and novice teachers’ experiences with the implementation of collaborative learning (CL) in classroom practice, after a formal training pertaining to CL as part of their teacher education programme. The findings revealed several dilemmas in the stories of student and novice teachers that illustrate the conflicting options teachers are facing in relation to their colleagues, their pupils, the curriculum and in the classroom context when implementing CL. In particular, the following dilemmas were identified: two dilemmas related to professional autonomy (student teachers: teacher autonomy vs. pre-service performance assessment and novice teachers: teacher autonomy vs. institutional conformity).