The purpose is to document the ongoing development of two schools in becoming professional learning communities and the effects of meaningful collaboration on teacher learning. The question that guides this research is: How does a school become a sustainable professional learning community? The theoretical framework is based on the work of Senge, Hord, Fullan, Hargreaves and Fink, and Stoll, McMahon and Thomas and includes the areas of professional learning community, change and sustainability. Finally, the study addresses the relationship between professional learning community and school culture. The methodology involves a qualitative case study approach designed to gain information regarding two emerging schools in their journeys toward developing learning community cultures. Findings reveal the stories of each school as they evolved as PLCs and the similarities and differences that emerged. Knowing that sustaining the culture of a PLC is complex, and not to be achieved without determination and growth, we look ahead at challenges to be addressed and further research to be conducted. Finally, we offer some concluding statements and attempt to relate findings to the literature on PLCs. The intent is to identify some of the intricacies in building cultures of learning for adults and students. As we have learned through these two stories, many things happen simultaneously, to greater or lesser degrees, at varying points in time over a period of years that seem to influence the development of a PLC. Such development seems so complex that to be able to describe discrete steps or stages is unlikely. Still we are beginning to see that some categories of activities and issues must be developed before others can emerge.