Teachers' professional development in Schools as Learning Communities may become a key process for the sustainability and transferability of this model worldwide. Learning Communities (LC) is a community-based project that aims to transform schools through dialogic learning and involves research-grounded schools that implement Successful Educational Actions (SEAs). More than 600 such schools in Europe and South America, many of them located in high poverty areas, have shown a reduction in drop-out rates and an increase in school quality and attainment. This article analyses how teachers' professional development is built in these schools. Following a communicative methodology approach, we analyse the implementation of the programme in four schools in South America. The main features are grounded in transformative theories and socially responsive research and provide evidence-based arguments and practical knowledge for effective implementation built upon egalitarian relationships and communication within the entire community.