In this paper, the practices of mentoring in Finland and New South Wales, Australia are studied in a comparative research design. More particularly, our aim is to investigate the social preconditions or arrangements (practice architectures) which prefigure (enable and constrain) mentors’ work and their understanding of their role (Kemmis & Grootenboer 2008; Kemmis & Heikkinen 2012). As such, the key research questions of this study are: How do mentors in these two different contexts understand their role as mentors, and how are the practices of mentoring prefigured?The study is based on empirical material of mentors’ practices in both countries. In Finland, a peer-group mentoring model (PGM) for supporting professional development of teachers has been introduced since 2010. The model is based on the ideas of socio-constructivism, dialogue and knowledge sharing. Under the concept of ‘Paedeia Café’, peer-group mentoring has been offered not only to new teachers but student teachers in their last year of pre-service teacher education. The data collected for the present study consists of semi-structured interviews with six mentors running the ‘Paedeia Café’ peer-mentoring groups. The interviews explored the mentors’ views of mentoring and their mentor role. In Australia, New South Wales, new scheme teachers are assigned a mentor. Often this mentor is a senior teacher assigned by the school principal whose responsibility it is to guide the new teacher through the processes required to attain accreditation at ‘professional competence’. The data analyzed in this study were collected in 2013 in a rural educational context. The interviews explored the mentors’ perspectives on mentoring and the ways in which this professional relationship served to enable and transforme professional and pedagogical practices. The data analysis comprise two phases. Firstly, the data has been analyzed separately in the different contexts. An inductive approach including content analysis was applied. Secondly, the two cases and the initial analysis have been compared and analyzed in relation to the theory of practice architectures. The preliminary findings show that there are significant differences in the preconditions (practice architectures) which prefigure mentors’ work and their understanding of their role. In Finland, the social equity between teachers is emphasized, the meetings are held in a highly informal manner, and there are practically no elements of control or monitoring of teachers. In Australia, mentoring practices seem to assume traditional a novice- expert orientation towards mentoring and is highly regulated and structured.