This article considers how documentation as a professional development tool acts as a change agent for teachers and how collective engagement in the documentation process mediates the inherent tensions of working and learning in a group. Three groups of educators, at three distinct schools, used Reggio Emilia-inspired documentation as the mediating activity through which to construct collective discourse, enhance professional development, and grow collaborative inquiry. Changes in culture and practices at each site are framed through the tensions and subsequent group shifts these educators experienced as they structured their collaborative practices, developed intentional experiences, and cultivated collective ownership of the process. Managing the challenges that emerged both strengthened the community of learners and enhanced teachers' abilities to observe, record, analyze, represent, and respond to the teaching and learning that occurred in their classrooms, ultimately changing the culture of their learning communities. (Contains 1 table.)