Background: There has been relatively little analysis of school context including a large number of elements from the broader social, political and economic influences. However, primary schools in Flanders (Belgium) are supposed to consider their school context when implementing the Flemish policy on equal opportunities in education. Purpose: In order to provide a better underpinning for a contextualised policy, a multidimensional concept of school context is used to identify the position of Flemish primary schools in the field of education and to outline their profile. Sample: The position of these schools was analysed with survey data from the longitudinal study "School careers in primary education" (SiBO), supplemented by administrative data from the Flemish government. The sample used for this analysis contains 113 primary schools with an overrepresentation of schools receiving additional resources to implement a policy on equal opportunities in education. SiBO collected information from several stakeholders: the pupils and their parents, the teachers and the school principals. Design and methods: The survey results were analysed statistically. A latent class analysis (LCA) was carried out to cluster schools into more or less homogeneous groups. School context is made up of different kinds of resources. These are latent constructs that are not directly measurable. Therefore, social, cultural and economic capital are operationalised with concrete, measurable indicators related to the school infrastructure, the catchment area and the human resources. Results: The analysis shows that there exist clusters of schools with common contextual features. The LCA reveals three classes: medium-resource schools, low-resource schools and high-resource schools. As a result, this study identifies hidden resource inequalities between primary schools in Flanders. Conclusions: We conclude that the field of education is not a level playing field. Despite equality in funding rules or indeed, despite educational priority funding, school contexts and resources can differ strongly between "advantaged" and "disadvantaged" schools. The findings are relevant for policy makers aiming to improve equal opportunities in education and contribute to the "contextualisation agenda" of educational research.