Drawing on a study of a Swedish secondary school with a heterogeneous intake, this article provides an analysis of the social relations and segregation within an individual school. As shown in the analysis, young people from different socio-economic backgrounds were largely separated in school, differently positioned and in conflict with each other. The pupils typically referred to the segregation and conflict as ethnic, although strongly underpinned by economics and class. Some of the pupils' and staff's wish for a less segregated schooling suggested potential openings for the relations between the groups. However, this was judged to go against the will of resourceful groups of parents with whom the school leadership felt they had to comply. Central to this was parents' freedom to choose the school, which worked in this context to further the segregation within the particular school.