Attention deficit hyperactivity disorder (ADHD) is popularly understood to be a condition which resides in the person. In this scenario, the school is an innocent bystander, a container for the 'maladjusted child'. Drawing on an ethnographic case study of one classroom, the first stage of doctoral research into the production of the diagnosis of ADHD, we argue that the school is complicit in the construction of the (dis)order. It is the micro-practices of routinisation, material manifestations of normative discourses of good behaviour and a medicalised episteme that include some children, while excluding others. Those who fail to conform to the norms are singled out for 'special' (education) treatment, one form of which is a diagnosis of ADHD.