This article examines the integration of Education for Sustainable Development (ESD) in the French educational system and more especially in primary schooling. The research question concerns the purposes, the form of integration and the definition of the content of ESD. To answer these questions, I present and analyse the main features of these three questions as presented in the official texts of the Ministry of Education. I also draw on a case study focusing on the integration of ESD at primary level. Thirty-four semi-directive interviews were carried out with local ESD actors working in two communes in southern France. In this study, the interviews were subjected to thematic analysis using NVivo 12 software. The results show that, both in the official texts and in the discourse of the interviewees, the purposes of ESD tend to be civic and emancipatory. Furthermore, while the choice of content is left to the actors on the ground, the incoherence and lack of clarity of the official texts complicates their task. They thus have difficulty in setting ESD projects within an interdisciplinary approach.