Abstract Pupils health indicators and behaviors are marked by social and territorial inequalities which develop early (DREES, 2015, 2019). In order to combat these inequalities and improve the health behaviors and well-being of pupils, the “health-promoting school” approach is recognized as convincing. It is endorsed by the World Health Organization (Langford, 2015; WHO, 2021). The health policy currently implemented in French schools is convergent (MEN, 2018, 2021). In order to disseminate this policy, since 2019, the Alliance project has been implemented in 101 French schools (9 - 12 years old) and 97 municipalities in the AURA region. Each school and community are trained and supported to promote the development of professional practices and a health promotion project to improve the health behaviors of pupils. The question arises as to the extent to which the development of health-promoting teaching projects and practices participating in the strengthening of health protective factors - life skills and health literacy - of pupils would have a mediating effect from the point of view of socio-economic level and health behaviors of pupils? Each year, data are collected from pupils by questionnaire, mesuring their well-being, health habits, psychosocial competencies and their families’ socio-economic level. 11500 questionnaires collected during 3 years have been analyzed. Descriptive and bivariate analysis indicate sevreral improvements between years in their health habits like for example daily physical activities (6% for T0 and 16% for T2) or daily consumption of sweets (17% for T0 and 13% for T2). They confirm negative influence of risk factors as low socio-economic level on health habits. But mediation analysis show that psychosocial competencies, especially emotionnal and social competencies, mediate significatively this influence (mediation effect range from 5% to 21%). Key messages • The health indicators and behaviors of young people are marked very early on by social and territorial health inequalities. • Health-promoting school approach and particularly – life skills and health literacy – would have a mediation effect on health behaviors and the socio-economic level of students.