This research explores the experiences of a group of academics learning to teach with problem-based learning (PBL) and how a community of practice (COP) supported this transition. An action-research project evaluated both PBL experiences and group processes. Teachers were enthusiastic about PBL but experienced a variety of problems during the transition. Those new to teaching had particular difficulty taking on the PBL role of "facilitator". All teachers struggled to work within the "rules" of PBL. Of specific concern was the varied input teachers provided for their tutor groups and possible inequalities for student learning. The COP enabled professional learning about teaching PBL, but the dynamics of the group were perceived as too hierarchical. The group could have functioned better if it had adopted the principles underpinning a COP so that teachers could take a more critical stance towards how they operated within the group and how they taught PBL.