The current short-term longitudinal study evaluated whether anger and sadness regulation moderated the associations between peer victimization and physical and relational forms of aggression over a 6-month period. Participants included 278 predominantly Caucasian children (51.8 % female) between 8 and 12 years of age (M = 9.33, SD = 0.99). Peer victimization was assessed at Time 1 using child- and teacher-reports, and teachers provided ratings of children’s aggressive behavior at Time 1 and Time 2. Children also completed self-report measures of anger and sadness regulation at Time 1. Results from multilevel models provided support for the notion that children’s ability to effectively regulate their feelings of anger and sadness influences the relations among peer victimization and forms of aggression over time. As anticipated, high levels of anger regulation attenuated the link between child-reported peer victimization and physical aggression. Further, when levels of anger regulation were high, teacher-reported peer victimization predicted subsequent decreases in physical aggression. Contrary to expectations, however, high levels of anger and sadness regulation exacerbated the association between child-reported peer victimization and relational aggression, and teacher-reported peer victimization predicted decreases in relational aggression over time when levels of anger regulation were low. Directions for future research and implications for practice are discussed.