This article looks into how masculinities are constructed in a mother tongue fifth grade reading classroom in Rio de Janeiro by focusing on the stories pupils tell one another in this context. The article follows a socio-constructionist view of discourse and social identities, such that stories are taken as resources used in the construction of social life and social identities or as instruments through which we act in the world and construct it. The stories are analysed in relation to how boys and girls position themselves towards tellers, listeners and characters, and how they draw upon socially available coherent systems. The study adopted an ethnographic approach that allowed naturally occurring stories to be audiotaped in classrooms or in focus group interviews. The analysis reveals that the stories (narratives, chronicles and explanations) told in schools help to construct hegemonic masculinity by drawing on coherent systems available in everyday common sense knowledge. Ways of destabilizing common sense notions of "masculinity" by employing narrative analysis within language education are suggested. (Contains 2 notes.)