Children's ethnic outgroup attitudes are influenced by their teachers' beliefs and multicultural education. However, research has ignored the possible impact of interpersonal relationships with teachers on students' ethnic attitudes. Three studies, using comparable datasets gathered among native Dutch children (8–13years) attending grades 4 to 6 in elementary schools in the Netherlands, assess the importance of student-teacher relationships. In Study 1 (N=389), student-teacher relationships were found to be associated with more positive outgroup attitudes, independent of factors commonly used to explain children's outgroup attitudes. Study 2 (N=334) replicated these findings and showed that the impact of student-teacher relationships was not a reflection of the perceived teacher norm on multiculturalism. The results of Study 3 (N=308) show that the association between close student-teacher relationships and children's ethnic attitudes is indirectly associated through internal motivations for intercultural openness, but not through external motivations or intergroup anxiety.