The triarchic model of psychopathy was advanced to reconcile differing historic conceptions of this condition and alternative approaches for assessing it. The current study was undertaken to expand the empirical evidence base for the triarchic model by examining its correlates in adolescents, with measures of particular relevance to developmental theories of antisocial behavior. Self-report scales assessing the triarchic constructs were administered along with measures of conduct problems, callous-unemotional traits, attachment style dimensions, negative emotionality, and hyperactivity/inattention to 608 Italian adolescents (272 girls; M age = 16.70 years). The disinhibition dimension of the triarchic model was related most highly to general externalizing outcomes, such as conduct problems and hyperactivity-inattention, in this adolescent sample. The meanness dimension was selectively related to callous-unemotional traits and other measures of limited prosocial emotions and to affiliation motives that emphasize social gain. Triarchic boldness was associated with greater emotional stability and greater confidence in peer relationships. Of interest, an interaction between meanness and boldness was evident in predicting a lower need to understand one's own and others' emotions. These results provide a valuable illustration of the potential of the triarchic model to help advance developmental models of antisocial behavior in youth. Public Significance Statement This study examined how dimensions of psychopathy described by the triarchic model relate to measures of problem behaviors and affective-interpersonal style in an adolescent sample. Scores on the three triarchic dimensions-disinhibition, meanness, and boldness-showed meaningful contrasting relations with conduct problems, hyperactivity/inattention, callous-unemotional traits, emotional proclivities, and attachment style dimensions. This work illustrates how the triarchic model conceptualization can help advance developmental models of the emergence of antisocial behavior.