The use of mentoring group conversations as a tool to support pre-service teachers' professional development has become more common. However, there is still a lack of research that shows how conversations are used to develop knowledge. The present paper is based on ethnographical observations of mentoring group conversations, and describes how pre-service teachers who participate in an obligatory mentoring model use their conversations as an arena in their search for professional knowledge. Three areas were focused upon during the conversations: the teachers' role and teaching practice, conditions for professional development and conditions related to the profession. The pre-service teachers mainly used conversations to question, discuss, share and reflect over pedagogical and didactical dilemmas related to teaching activities in the classroom and to their own as well as other teachers' behaviour and attitudes in different situations. The paper provides an insight into how a mentoring model can contribute to professional preparation.