The aim of the current study was to investigate whether the association between parental attachment and externalizing behavior is parallelly mediated by dysfunctional emotion regulation and callous-unemotional traits. The community sample included 296 adolescents (M[subscript age]?=?14.90, SD[subscript age]?=?1.31), who completed the Inventory of Parent and Peer Attachment, the Inventory of Callous-Unemotional Traits, the Regulation of Emotions Questionnaire, and the Youth Self-Report Child Behavior Checklist. A mediation analysis revealed both direct and indirect effects. Secure attachment representations were negatively associated with internal- and external dysfunctional emotion regulation strategies and callous-unemotional traits, which in turn were positively associated with externalizing behavior problems. The current study expands previous research by simultaneously investigating familial and cognitive factors that foster externalizing behavior problems. An attachment-based perspective offers new possibilities for theory expansion, research directions, and the development of interventions.