Currently, there are many educational centres that demonstrate the need to promote initiatives to improve coexistence at school at the international level, especially in those located in contexts of social vulnerability. A socio-educational programme has been developed, applied and evaluated at a Singular Education Action Centre (Centro de Acción Educativa Singular--C.A.E.S) in the city of Valencia (Spain). To ascertain the programme's impact and possible generalization to other contexts, a quasi-experimental pretest-posttest design with a control group was used. Information was collected from 297 students and 54 teachers based on questionnaires assessing coexistence at school. The results obtained demonstrate the satisfactory functioning of the programme. The faculty and students from the experimental group affirm the importance of continuing to work in this direction to invest in creating a democratic school that firmly believes in coexistence and participation. Areas for improvement include the need to incorporate actions to increase family participation and develop strategies to facilitate the implementation of a more comprehensive programme.