Predominant patterns of classroom talk and interaction are notoriously difficult to change. In this paper, we consider teachers’ use of transcription as a means to change classroom interactional practices during the course of their action research projects in primary school classrooms. We draw on data generated in twelve action research projects and address the following question: how did developing and using transcripts influence teachers’ action research projects? Thematic analysis of teachers’ reflective journal and of final interviews with teachers is employed. We delineate four themes: transcripts as accounts of what actually happened, ways of working with transcripts to identify a problem, transcripts as evidence to inform the change process and, engaging with transcription and transcripts as an evocative experience. Through our consideration of the themes, we establish the usefulness of teacher-developed transcripts for action research but the taken-for-granted nature of transcription itself. In conclusion, we argue that action research studies that incorporate more extensive knowledge of the process of transcription would create potential for more focused reflection over the course of action research studies and would enhance practitioners’ understandings of talk and interaction in classrooms. Addressing transcription through professional development would be one important way to support practitioners.