Although childhood aggression is typically associated with peer rejection, some children concurrently employ coercive and socially skilled behavior and successfully avoid negative peer outcomes. However, research on children's dual use of coercive and social behavior has largely employed cross-sectional designs with nonclinical populations and, as a result, little is known about the covariation of aggression with social skills, particularly among high-risk samples. We directly addressed this limitation by testing childhood aggression and social skills as separate time-varying predictors of prospective change in peer rejection in a sample of children with and without attention-deficit/hyperactivity disorder (ADHD). Two hundred and two 5–10-year-old children (M = 7.9 years, SD = 1.2) with and without ADHD were followed prospectively for 6 years. Key constructs, including children's overt aggression, social skills, and peer rejection, were collected at each of the three waves using multiple methods and informants. Controlling for demographic factors and time-varying ADHD symptoms, longitudinal change in child-, parent-, and teacher-reported aggression positively predicted prospective change in parent- and teacher-reported peer rejection. Importantly, predictions were moderated by parent- and teacher-reported social skills, such that aggression inversely predicted peer rejection for children with high social skills. These results demonstrate that social skills meaningfully alter trajectories of peer rejection predicted from cross-time variation in aggression. We discuss the theoretical and empirical implications of these findings within a developmental psychopathology framework, including recommendations for directions for future research.