This study examined changes in and predictors of preference for same-ethnic friendships among German (N = 106) and Turkish (N = 45) preadolescents (M age = 10.4 years) during their 1st year in an ethnically heterogeneous school. Drawing on the contact hypothesis, it examined the relation between children’s attitudes and their preference for same-ethnic friendship. Among both German and Turkish children, the latter decreased over time and its variability was predicted by intergroup attitudes and peer norms about cross-ethnic friendships. Outgroup orientation and perceived contact conditions predicted only German children’s preference for same-ethnic friendships. Over time, classroom identification increasingly reduced preference for same-ethnic friendships among Turkish children. The results showed that interindividual attitudes were related to children’s level of intergroup contact.