The living environment plays a critical role in overall well-being, particularly during childhood. The positive impact of green spaces on health has been widely demonstrated (Lee and Maheswaran, 2011; Tzoulas et al., 2007) as well as the detrimental effects of air pollution (Landrigan et al., 2018). Moreover, compelling evidence indicates that exposure to nature during childhood contributes to improve cognitive development and mental health (Engemann et al., 2019; Vanaken and Danckaerts, 2018). Children are also highly susceptible to pollution-related diseases (Landrigan et al., 2018). At the same time, socio-environmental inequalities present significant challenges within our societies. The most vulnerable population groups are often exposed to environments with limited green spaces (Schüle et al., 2019) and higher pollution levels (Fairburn et al., 2019). Furthermore, the undesirable and cumulative environmental exposures that children from low socio-economic backgrounds experience at home are also present in schools (Bolte et al., 2010). In this study, we explored the association between the socio-economic status of the pupils and the school environment in the Fédération Wallonie-Bruxelles, which encompasses French-speaking schools in Brussels and Wallonia, Belgium. We specifically investigated the levels of greenness and air pollution around the school establishments. Our main hypothesis was that children from low socio-economic backgrounds are more likely to attend schools located in environments with low levels of greenness and high levels of air pollution. Additionally, we investigated potential variations in this relationship across various settings. We considered different types of areas, including rural, urban, and high-density areas (Eurostat, 2018). We also examined potential differences in this association across specialized education programs and different educational levels: kindergarten, primary, and secondary levels. Lastly, we investigated variations among different educational networks : in ...