In this article, young people’s hypermasculine performances of gender in a Danish institution for young offenders are analyzed. Through the ethnographic method of detailed observations of two situations of young people, one male and one female, entering an institution for young offenders, it is demonstrated that hypermasculinity is created as a collective frame of meaning creating both possibilities and restraints in concrete situations. Hypermasculinity is often discussed in relation to criminality as an intensification of hegemonic understandings of what constitutes a "real man" and thus as part of male offender’s identity formation. In this article, the relational analysis shows that hypermasculinity is not alone to be understood as the expression of the individual young person’s performances but rather as the dominating institutional frame guiding all gender performances. The observed hypermasculine frame comprises notions of a real man based on performances of overt sexuality, the willingness to commit violence, and the limitation of subversive performances.