Numerous primary and post-primary communities of practice (CoP) are used as educational change mechanisms to support teachers improving physical education (PE) practice in Irish schools. This study's purpose was to examine perspectives of program facilitators and participants of Irish PE CoP created to address teachers' interests. Specifically examined were views of successful professional development and characteristics supporting or hindering its success. Participants included 33 teachers and 7 facilitators. Analysis identified three themes: purpose and success, guideposts, and roadblocks. Views of success paralleled CoP defined purposes. Incentives, a positive learning environment, supportive emotional environment, structure of the group, and facilitation with care were guideposts. Roadblocks hindering success included: time, ineffective learning environments, policy, the status of PE, and the context of schools and teaching. Overall, varying CoP structures, leadership, and support recognized multiple aspects of teacher capacity building. (Contains 1 table.)