This study investigates discriminatory peer aggression among primary school aged children as a function of minority status (based on nationality, ethnicity, religion) of the target and the relative proportions of minority and majority children in the school. Participants were 925 8- to 12-year-olds attending schools in Britain. Children of minority status were no more likely than children of majority background to experience peer aggression in general. However, minority children were more likely to experience being the victims of discriminatory aggression. Two contrasting predictions were tested: that discriminatory aggression would be more likely when the minority group was relatively small in number or, alternatively, that as the proportions of children of minority backgrounds increased across schools, discriminatory aggression would be greater. The latter hypothesis was supported. Findings also revealed that in schools with a lower minority presence, discriminatory aggression experienced by majority children was significantly lower than that reported by minority children. When the school minority rate exceeded 81%, discriminatory aggression was more commonly experienced among majority children than among minority children. Copyright © 2011 John Wiley & Sons, Ltd.