The paper is based on work conducted in my dissertation that aims to explore gender constructions in preschool, preschool class and the first grade. In the analysis, gender constructions as they appear in children’s interactions and between children and adults are explored. Barrie Throne’s (1993) concepts borderwork and crossing are of theoretical importance in the study. The dissertation consists of two studies based on different sorts of empirical data. In the first study, video recordings from the FISK project [The Preschool and School in Collaboration Project] are re-analysed. The analysis takes its starting point from conversation analysis (CA). The second study consists of data collected from a separate fieldwork carried out in a preschool class, for which I have been personally responsible. On the whole, the analysis shows that borderwork situations are more frequent than border crossing. Gender boundaries were strengthened by the way the teachers interacted with the children. Also the children were part in this as for how they reacted to behaviour that was considered inappropriate. Especially boys experienced this, but what differs from previous research is that boys more frequently challenged gender boundaries. The recurring borderwork situations raise questions about equality in preschool, preschool class and school.