The aim of this study is to illuminate preschool teachers’ perceptions of the significance of the mother tongue for children in preschool and the factors that influence the extent to which mother tongue and multilingualism are made visible in education. The study is based on qualitative semi-structured interviews with six preschool teachers in a municipality in central Sweden. The data was analysed using a combination of semantic and latent thematic analysis to identify both explicit and underlying patterns in the participants’ descriptions. The theoretical framework is based on Nira Yuval-Davis concepts of belonging and politics of belonging, including the perspective of situated intersectionality. Findings show that preschool teachers primarily perceive the mother tongue through an instrumental lens, emphasizing its importance as a tool for learning the Swedish language. While its significance for identity, recognition and emotional well-being is acknowledged, these aspects often remain secondary and implicit. Furthermore, the study identifies several factors that condition the work with multilingualism, such as structural and material constraints, pedagogical uncertainty and unexamined linguistic norms. The study concludes that the relationship between mother tongue and belonging is complex and conditional. Children’s opportunities for belonging are shaped by politics of belonging where linguistic hierarchies and majority norms influence which languages are given space. The results suggest a need for a more systematic approach and competence development to ensure that children’s right to their mother tongue is realized as a fundamental part of an inclusive preschool environment.