Previous academic research which focused on girls’ behaviour tended to do so by looking at behaviour in terms of the extremes: by either exploring the perceptions and experiences of girls who appear to behave well, or alternatively, by researching girls who are categorised as extreme misbehavers, in institutions such as Pupil Referral Units. This ethnographic study was undertaken in a state secondary school setting over one academic year. The research centred on girls who were in Years 10 and 11, and is an exploration of the micro performances of their behaviour in the school. The ethnographic nature of the research allowed an in depth focus on girls’ micro performances in school. The feminist influenced thesis seeks to explore girls’ constructions of gender, how this is negotiated alongside their wider performances as pupils in the school and is subsequently recognised (by themselves and others), as performances of particular behaviour. The research draws on Goffman’s (1959) conceptualisation of performance and impression management, Butler (1990), theoretical notions of performativity and Foucault’s (19757:1978) theories of power, discourse and surveillance, to explore how gender and behaviour are being understood in this context. The study sought to explore the world from the girls’ viewpoint to understand the complexity of their experiences more fully. The research examines not only how the girls were positioned in terms of their perceived behaviour, but also how they responded to this positioning (their resistance and accommodation of these positions, and the shifting nature of these positionings across time) and how these were often perceived in relation to particular gendered expectations. The originality of the research stems from findings about issues of self-harm, panic attacks, authenticity, social media, middle class girls and fighting, which lie in the rich and detailed empirical data arising from the study. The significance of these findings draws these multiple threads together, giving insight into gender positioning and behaviour, and the study privileges the girls’ voices as they discuss their feelings and the effects of these issues on them, complicating previous research.