Australian policy contexts are promoting school transformation through teacher learning and the development of schools as professional learning communities. However, Australian practitioners have very limited contextualised research to guide their efforts in response to these policies. The researcher’s involvement in a school revitalisation process provided the impetus for this research study that investigates the practitioner experience of a developing professional learning community at RI College (pseudonym for a large independent girls’ school in Brisbane). This study endeavours to gain a more informed and sophisticated understanding of developing a professional learning community with the intention of ‘living’ this vision of RI College as a professional learning community. Praxis-oriented research questions focus on the practitioner conceptualisation of their school as a developing professional community and their experience of supporting/hindering strategies and structures. The study gives voice to this practitioner experience through the emerging participatory/co-operative research paradigm, an epistemology of participative inquiry, a research methodology of co-operative inquiry and mixed methods data collection strategies. Incorporating ten practitioner inquiries over two years, recursive cycles of action/reflection engaged practitioners as co-researchers in the collaborative reflective processes of a professional learning community while generating knowledge about the conceptualisation and supporting/hindering influences on its development. The outcomes of these first-person and second-person inquiries, together with a researcher devised online survey of teachers, were both informative and transformative in nature and led to the development of the researcher’s theoretical perspectives in response to the study’s research questions. As outcomes of co-operative inquiry, these theoretical perspectives inform the researcher’s future actions and offer insights into existing propositional knowledge in the field. Engagement in this practitioner inquiry research has had significant transformative outcomes for the co-researchers and has demonstrated the power of collaborative inquiry in promoting collective and individual professional learning and personal growth.