The educational approach views the community of practice as a community of teachers and students who share common rules and values, information and experiences through dialogue and collaboration. Three doctoral theses are in progress at the University of Athens which study the possibilities of creating a community of practice in three different educational institutions: a Centre of Environmental Education (KPE), a primary school and a nursery school. The prospect of developing a community of practice in the institutions was considered in the context of the vision and the principles of sustainability and the Education for the Environment and the Sustainability. We have chosen action research as the most appropriate methodology for our studies as we believe that its characteristics cohere with the philosophy of the community of practice. The first study focuses on the possibilities of creating a community of practice in a KPE. Teachers from different classes and subjects interact with each other, exchange views, facilitate relationships and build trust by participating in common activities. The second study focuses on the possibilities of creating a community of practice in a primary school. Students interact and collaborate with their colleagues, teachers and the other members of the school's staff by actively participating. The last study focuses on the possibilities of creating a community of practice in a nursery school. Students, teachers and parents collaborate and interact with each other, share values, beliefs and ways of doing things by engaging in real actions and creating powerful learning environments. All the people who got involved in the studies (teachers, students, parents and we as facilitators) were not accustomed to the idea that learning involves a process of participation in a community of practice. Although those difficulties emerged during the studies, we all agree on the crucial role of values such as collaboration, communication, relationship building and identity in the educational institutions.