Provided by the Foundation for Environmental Education (FEE), the Eco-Schools programme (ESP) is said to foster a student’s-led transformation towards sustainability at schools and their local community. It thereby constitutes an opportunity for students to develop their action competence needed to be able to engage in today’s sustainability challenges. Until now, there has been few qualitative research about the ESP and this thesis therefore aims to demonstrate how students are participating as active agents in the ESP. Through using Cultural-Historical-Activity-Theory (CHAT) as a conceptual framework, a rich picture of student participation in two distinct socio-cultural contexts (Netherlands and Spain) has been developed, which demonstrates the constitution of the students’ learning environment. CHAT allows to uncover certain contradictions within the activity system, which can be used as driving force in order to improve the condition of student participation in each local context. You are very welcome to join the presentation.