Central to a contemporary understanding of childhood is the developmental and clinical-medical construct of the 'normal' child. When judged to fall outside of culturally, socially and historically situated parameters of 'normality', children become labelled as 'deviant from the norm'; for instance, in mental health contexts where this may provide the basis for psychiatric diagnosis. However, judgements of a child's 'normality' are further complicated by the range of individuals who may have a stake in that construction, including parents/carers, professionals and the child themselves. Using discursive psychology, we analysed 28 video-recorded UK child mental health assessments, to examine ways that parents presented concerns about their children's development. They did this by drawing on notions of 'ab/normal', in ways that functioned to legitimise their need for services and built a rhetorical case to demonstrate clinical need; often by contrasting the child with other 'typical' children and/or contrasting the same child's behaviour in different settings or contexts. We concluded that given the growing crisis in child mental health, initial assessments play a crucial clinical role in determining diagnosis and labelling, and therefore, a critical discussion of these concepts and processes is essential.