This research insight discusses young people’s construction and display of gender in a mixed-sex floorball group in a Swedish sport school and explores in what ways gendered power relations were exercised. Observations of floorball lessons with 21 students aged 12–16 and interviews with 7 students were analysed through Lorber’s concept of gender as a social institution. Findings suggested that training in a mixed-sex group seemed to actualize a need to dichotomize and construct distinct groups of boys and girls, and a ‘boys are better than girls’ discourse prevailed. This was explained as being a result of their experiences of playing separately in floorball clubs during leisure time. All contributed to the construction of a discourse where boys were superior and girls inferior, although they were striving towards a uniform way to play. Their attitudes and actions indicated that while gender hierarchies were not transcended, they were, to some extent, negotiated.