i.07.03 Introduction.—Ecole 21® is an innovative initiative of the Franco-Belgian cross-border project “Générations en santé,” carried out under the Interreg IV program and co-financed by the ERDF and regional authorities. It brings together some twenty schools on both sides of the border, united in a collaborative effort that combines health promotion and sustainable development. Following three school years of pilot testing (2009–2012), an evaluation of the program’s implementation process was conducted in 2012 by the National Institute for Prevention and Health Education, drawing on the experiences of the organizations that implemented Ecole 21®: regional education and health promotion authorities in Champagne-Ardenne, Nord-Pas-de-Calais, and Picardy in France, and the provinces of Hainaut, Luxembourg, and Namur in Belgium. Method.- The evaluation was based on a document analysis of materials produced during the pilot phase (reports, charter, project overview, etc.), supplemented by a quantitative survey of Ecole 21® schools and twenty-two semi-structured interviews with schools and operators. Results.- The evaluation results highlight several factors that facilitate the implementation of such a program. Thus, the evaluators’ recommendations focus on the fundamental role of support provided to schools by the operators (Ireps, provinces). The rollout and sustainability of the Ecole 21® program would depend on the ability to maintain such support. In France, the close partnership between Générations en santé operators and the French Ministry of Education has legitimized and facilitated the implementation of the program. The two themes—health promotion and sustainable development—have helped maximize the impact of the actions implemented, particularly through the creation of a cross-disciplinary, multi-professional dynamic within schools. Finally, the initial steps toward establishing an Ecole 21® network, supported by two cross-border gatherings, have provided significant added value from a European and exchange perspective. Paper cited in the "Revue épidémiologique et de santé publique" in Supplement 4, Volume 61.