Many US teacher education programmes have developed learning environments in partnership with local school districts. A professional development school (PDS) is a learning organization formed through the collaboration of a university-based teacher education programme with its K-12 school partners. The resulting organization focuses simultaneously on the learning of school students and of preservice and inservice educators. This manuscript presents the PDS work of two different teacher education programmes and their alignment with the Standards for Professional Development Schools, published by the National Council for Accreditation of Teacher Education. The first and most important of the five PDS standards addresses the qualities of the learning community. The contribution of the standards to the viability of the PDS learning community as an emerging organization is discussed.