The aim of the paper is to develop knowledge about preschool teacher's professional development in activities based on a play pedagogical approach known as playworlds (Lindqvist, 1995). There is scant literature on teacher development that focuses on the teacher understood as a whole self -that is as a professional and a person. One exception is Ferholt and Lecusay's (2010) case study of adult-child mutual development in a playworld activity which highlights the potential of the playworld pedagogy for promoting qualitative changes in preschool teacher's pedagogical practices. We will apply the framework of relational pedagogy and particularly the concept of co-existence (Aspelin, 2011). The research presented draws on narrative analyses of transcripts of preschool teacher reflection meetings. These meetings were documented as part of an ethnography of three preschool units that incorporated a playworld approach during one school year in their Reggio-inspired classrooms. Informed consent was obtained from allthe teacher participants in this study. Participating preschool teachers described experiencing changes in their engagement at the preschool that were based on the integration of their professional and personal selves. This included a greater understanding of children's perspectives leading to a deepened connection with the children, and concomitant positive effects on collaboration between children and teachers. The teacher's attributed these changes to the ways in which in role-play with the children helped them step outside of their traditional role as teachers This research describes features of the playworld that promote this kind of holistic teacher development.