This paper explores the experiences of 14 early years educators who participated in a continuing professional development (CPD) programme coordinated by two of the paper's authors. The programme was part of a three-year research project, which aimed at introducing early childhood educators to an inquiry-based approach to mathematics and science education and involved participants as teacher-researchers and curriculum-makers in cycles of action research. From this CPD experience, teachers appeared to reconceptualize traditional teacher and researcher "roles" in more fluid and equitable ways, leading us to explore characteristics of the programme conducive to this shift. The main data source comprised teacher interviews, supplemented by video-recordings of group meetings, classroom enactment of activities and the facilitators' field notes. Findings suggest that the shift was encouraged by the gradual formation of a community of practice; a reconceptualization of the "practical"; and the epistemology-oriented approach adopted in mathematics and science education. The discussion highlights the implications of these findings for early years educators' professional development, and the problems of the "theory-practice" divide in such development. Furthermore, the discussion stresses the importance of the socio-cultural context in which such projects take place, particularly as these often draw heavily upon international literature.