Youth antisocial behaviour (ASB) is frequently considered to be displayed by children and adolescents who suffer from behavioural disorders. Consequently, attempts to reduce ASB have increasingly comprised mental health interventions. Moreover, early signalling of children at risk and early prevention of behavioural problems are regarded as crucial remedies. Critical investigations of these developments, however, are in particular concerned with the consequent medicalization of society and the behaviour exhibited by infants, children and adolescents. Consequently, the new Dutch youth law even refers to demedicalization as a central aim. From an ethical point of view, this article critically discusses the meaning and relevance of the medicalization reproach in the context of ASB. The aim is to show that the term medicalization (M) can reasonably be attached to three different developments: the biomedical turn (M1), an increase in (forensic) youth mental health care (M2) and early signalling and prevention (M3). The ethical implications of these developments, however, are diverse, referring to both risks and benefits. By itself, neither the term medicalization nor demedicalization carries a self-evident normative meaning. Therefore, a careful ethical analysis is needed to reveal which social developments are actually recommendable or disadvantageous.