Public health nurses (PHNs) are ideally situated to reduce health inequities and based on documents articulating their role, should be working upstream to promote equity, prevent chronic diseases, and improve population health outcomes. In reality however, numerous barriers contribute to lack of role clarity for PHNs, and this goal has not been attainable in practice. A common vision for PHN practice based on discipline specific competencies and full scope of practice has been identified as a priority by Canadian experts. The intention of this study was to develop a model to support PHN practice in an urban Canadian city. This study used a participatory action research approach, grounded in local experience and context. The action was the development of a professional practice model. Data were gathered using semi-structured interview guides during audio-recorded research working group (RWG) meetings from November 2012 to July 2013. A researcher reflexive journal and field notes were kept. The data were analyzed using qualitative methods. A significant feature was full participant involvement throughout the course of the study. A professional practice model was a key organizational tool that provided the framework to develop an autonomous PHN role and the structures necessary to support PHN practice within the health system. The professional practice model fostered full scope of practice and role clarity, with a focus on population health and equity, so that a consistent and evidence-based practice was attainable. The result was that RWG participants reported a shift in their practice, with greater awareness of theory. Participatory action research was essential in developing the framework and common language, and is a research methodology that should continue to be explored with nurses in Canada.