This study investigated the relationships between three psychopathic dimensions (callousness/unemotionality, grandiosity/manipulation, and impulsivity/irresponsibility) and reactive and instrumental aggression in a community sample of early adolescents (N = 243, age M = 12.29, SD = 1.18). The moderating role of moral disengagement (MD) was also tested. The findings from structural equation modeling (SEM) showed that impulsivity/irresponsibility was directly related to reactive but not instrumental aggression. Grandiosity/manipulation was related to both types of aggressive behavior. Moreover, MD was a significant moderator of these associations. Specifically, the positive relationship between grandiose-manipulative traits and instrumental aggression was stronger at high levels of MD. Impulsive-irresponsible traits were positively related to reactive aggression at only low levels of MD and negatively related to instrumental aggression at high levels of MD. Overall, our results highlight the enabling role of MD in aggressive behavior and show that this relationship varies for the different traits associated with psychopathy.