By adopting a developmental intergroup perspective (Killen & Rutland, 2011), this international symposium features research investigating students’ and teachers’ beliefs, social cognition, and attitudes regarding inter-ethnic bullying. The research focuses on European schools, where this phenomenon is spreading (Elamè, 2013). The first paper examines how students’ beliefs about their contact with the ethnic outgroup and about school climate are associated with bullying the ethnic outgroup. Among students of the majority ethnic group, evaluating the contact with the ethnic outgroup more negatively was related with higher inter-ethnic bullying, but a more negative evaluation of the school climate was associated with higher inter-ethnic bullying only for the students reporting more frequent contact with the outgroup at school. The second paper examines direct and indirect (through prejudice), and moderated (by the closeness to the teacher) associations of students’ moral disengagement with inter-ethnic bullying. Perpetration of inter-ethnic bullying was higher for students reporting higher moral disengagement, but the strength of this association was reduced in case of a warm relationship with the teacher. The third study explores whether teachers’ attitudes toward refugees can be influential on teachers’ evaluations of inter-ethnic bullying targeting ethnic minority Arab students. Teachers were found to be aware of wrongfulness of inter-ethnic bullying, but teachers who had more negative attitudes towards refugees showed to under-estimate the negative outcomes for the Arab victim from inter-ethnic bullying. The discussant will consider the findings in light of the international concern to reduce bullying and promote positive peer relationships in childhood and adolescence.