Previous research has demonstrated that school processes can be significantly associated with (in)equality in schools. However, it is unclear what these practices in schools look like. This study aims to understand support practices for students in primary schools in a highly selective education system. The findings are based on a contrastive case comparison of five primary schools in Switzerland with a large percentage of children with a migration background. Quantitative surveys with students in Grades 4, 5, and 6 (n = 372) and qualitative analyses of group discussions with teachers were conducted. The results of the qualitative study, and in part also of the quantitative study, show that schools differ systematically in providing support for students. None of the schools was found to have a support milieu that could be described as non-discriminatory. In the majority of the schools, the support milieu is oriented towards high performing students with a higher socio-cultural family background or high educational aspirations; this may lead to the reproduction of inequalities. Only two schools seem to have implemented compensatory support strategies, at least partially. Further, the schools can be differentiated regarding the teachers’ perceived degree of their active participation in supporting students.