Professional learning community (PLC) is a current "buzz" term in business and educational contexts, seemingly referring to anything from decision making committees to regular meeting groups or collegial learning teams. This paper explores the concept of a PLC within three significantly innovative schools, based on an examination of the relevant literature and also focusing on surveys and interviews. Findings indicate that, while there is broad consistency across the literature and within the innovative school cases in terms of core PLC elements of shared vision and values, collegiality, joint practical activities and student learning data, teacher inquiry and leadership support and opportunities, there are some pivotal PLC characteristics which heighten the professional learning impact. In this paper, using vignettes from the case study schools, these pivotal characteristics are related to developmental phases of PLC establishment. This offers valuable insights about nurturing more learning-focused PLCs, with significant benefits for teacher professional growth and ultimately for student learning.