The study investigates peer acceptance and victimization of immigrant and Swiss children in kindergarten classes. Our first aim is to compare peer acceptance and victimization of Swiss and immigrant children. Secondly, we explore the role of their local language competences (LLCs). The sample was drawn from kindergartens in communities in the German-speaking part of Switzerland. A representative sample of 568 boys and 522 girls (mean age 5.8 years) took part in the research. Teachers completed questionnaires on children's victimization, bullying, and LLC. The nationality background of parents was indicated by teachers and parents. To assess peer acceptance, a peer nomination method was used. Immigrant children showed less acceptance by peers and were more often victimized than their Swiss peers. There was a significant interaction effect for LLC and national background of mothers, showing that LLC was positively associated with peer acceptance for children of an immigrant background but not for Swiss children. Furthermore, peer acceptance mediated the effect of national background of mothers on victimization. Results are discussed in terms of the need to improve immigrant children's LLC.