The sustainability pedagogy has been considered a central framework for projects in Education for Sustainability due to its importance of equipping people with knowledge, values, skills, attitudes, and behaviors compatible with sustainability. Despite its theoretical-practical importance, there is still a gap in works that demonstrate its actual effectiveness. This work presents the outcomes of the Education for Sustainability Project (EfS) (2010-2016) developed by high school teachers and students in Sao Paulo, Brazil. The EfS considered a particular sustainability pedagogy as a guide for its activities and interventions in the school through active learning methodologies and multi-stakeholder social learning. Its effects and impacts on participant students' knowledge, actual behavior, and behavior intention were assessed quali-quantitatively by open-ended questions pre and post-tests. The participant students presented marked changes in knowledge and behaviors (compared to a control group) considering the adopted sustainability pedagogy, evidencing its effectiveness as a framework for different projects aiming at the formation of more sustainable individuals and societies.