This in-depth case study explored the ways in which adolescent boys, aged 16 to 18 years, explored their identities in relation to the formation of masculinities within the formal and informal spaces of a second-level school. Specifically, it attempted to uncover what is problematic about teenage boys’ understandings of gender identities within the context of a coeducational second-level school environment in rural Ireland. The study draws on young-person-centred interviews with small groups of adolescent boys and girls and individual interviews with male and female teachers. Particular focus is given to the narratives which show how adolescent male identities are constructed, negotiated and policed. This thesis examined the link between peer relationships and emotion practices of adolescent boys and showed that a high percentage of boys associated tough, stoic self-presentations to manliness and assiduously avoided displays of emotional pain and effectively discouraged such displays in other boys. The normative presence of heterosexuality in this school is revealed by highlighting how certain male students use homophobia in order to reinforce their dominance over other males who are perceived as subverting normative notions of hegemonic heterosexual masculinity, and for marshalling the boundaries of heterosexuality amongst boys’ peer groups. Homophobia and sexism is also revealed through the narratives of some teachers. Displays of power over the feminine were evident through sexism, control of public space by boys and a multiple of micro-practices revealing the construction of a hegemonic and resistant patriarchy in this school. The thesis concludes by suggesting that the absence of programmes addressing masculinities within second-level education system in Ireland is a matter of concern and is resulting in some boys adhering to the toxic elements of hegemonic masculinity. This can lead to reckless lifestyles, antisocial and destructive behaviours, well-being and mental health issues for boys.