This article provides an initial exploration of the impact of teachers' involvement with classroom-based research projects on their professional learning. Interviews with classroom teachers are used to explore their experiences of working with Graham Nuthall and his research teams, who focused on finding out how students' interactions with teaching events affected their learning. The aim was to investigate whether teacher involvement with research on and about their own classrooms contributed to their professional learning, changed their teaching practices, and made a difference to their professional career paths. This study draws on the literature around effective teacher learning and compares it with the impact of teacher involvement with the Nuthall classroom research projects.