This study examines teachers' perceptions of the specific factors and conditions which shape international communities of practice as successful vehicles for their professional development. Data were collected through semi-structured interviews with thirteen teachers in Poland who have extensive experience working in a wide range of international professional development settings. The findings indicate that teachers perceived international communities to be a unique platform for their professional development because they offered multi-layered topographies for professional growth; created space for the collective organisation of development activities in diverse, autonomous teams working on challenging topics; and allowed for sharing teaching stories, reflecting on practice, as well as feeling affirmed/affirming others. Based on the results, recommendations are made for future research and policies which enrich communities within and across schools by providing teachers with the flexibility to discover and build international communities.