Age of onset, callous-unemotional (CU) traits and anger dysregulation have separately been proposed as relevant factors in explaining the heterogeneity of antisocial behaviour (ASB). Taking a dimensional perspective, this study examined the specific contributions and the mutual influences (i.e., interactions) of these three characteristics on specific dimensions of ASB (i.e., criminal behaviours and externalizing symptoms). Assessments were conducted on 536 youths from institutions with the youth psychopathic traits inventory (CU traits), the Massachusetts youth screening instrument-second version (anger dysregulation), the criminology questionnaire (criminal behaviours) and the child behavior checklist (externalizing symptoms), rated by both the youths and their carers. Using Bayes as estimators, the results revealed that the number and frequency of crimes (and, more specifically, damage to property, property offenses and media crimes) were explained by a specific contribution of each factor (age of onset, CU traits and anger dysregulation). Additionally, the interactions between age of onset and CU traits or anger dysregulation were relevant predictors of some types of crimes (i.e., damage to property, property offences and media crimes). Furthermore, when rated by youths, externalizing symptoms were explained by CU traits and anger dysregulation. However, when rated by the carer, anger dysregulation was more important in explaining externalizing symptoms. This study highlights the importance of considering these factors altogether and the value of using a dimensional perspective when examining the structure of ASB in youths. Consequently, future classifications should take into account the mutual account of these characteristics, which were previously studied separately.