This investigation examines whether negative interparental conflict strategies (stonewalling, triangulation, verbal aggression, and physical aggression) and parenting styles are related to social and physical aggression with peers for children followed longitudinally from age 9 to 10 (N = 256). Parents reported on negative conflict strategies and parenting styles at the beginning of the study and teachers rated children's social and physical aggression with peers when children were in the 3rd and 4th grades. Structural equation modeling demonstrated that, for girls, mothers' negative interparental conflict strategies were positively associated with both social and physical aggression with peers. Mothers' negative conflict strategies were not related to boys' social and physical aggression at school, fathers' negative conflict strategies were not related to aggression for either gender, and no relations emerged for parenting styles. These results offer partial support for a same-gender modeling hypothesis and suggest that girls' social and physical aggression at school may be related to watching mothers resolve marital disputes by engaging in triangulation, stonewalling, and verbal and physical aggression with partners.