This study characterizes nongovernmental organization "Ação Educativa" as an institutional entrepreneur, once it introduces social innovations in education fields. The NGO develops projects with public schools in São Paulo, Brasil, regarding best integration and social development. In the process of institutional changes, we identified social innovation experiences and resistances. This is an interpretativist case study paper. The results show how organizational changes were made in the public schools. We intend to contribute to NGO studies and their ability to generate social innovation.