This study investigates teachers' understanding of how conversations between colleagues can promote the development of knowledge. Its purpose is to supplement previous research in the field of knowledge processes in respect of conversation as an integral part of teachers' everyday work. On the basis of interview data obtained from teachers in a Norwegian school context, the study concludes that conditions for knowledge development in conversations between colleagues exist because teachers set the agenda for their collaboration and they raise issues from their pedagogical practice and explore and challenge these in depth. Based on theoretical perspectives and international research in the field, it is argued that, despite the fact that teachers themselves are being challenged to take responsibility for knowledge development in the teaching profession through collective knowledge processes at a micro level in the school organisation, it will be important to have support structures at different levels of the educational system to prevent them from standing in a vacuum.