Intimate partner violence and insecure attachment are therapeutically relevant concepts when working with couples. The link between attachment and intimate partner violence has been examined in the literature, but an area of aggression that often goes unexamined is relational aggression, or using third parties as a means of being aggressive toward a partner. We asked how participants' attachment behaviors were related to their own and partners' relational and physical aggression. We used structural equation modeling to estimate actor–partner interdependence among these relationships in 644 heterosexual couples. Results indicated significant partner paths from attachment to relational aggression, as well as significant actor paths between relational aggression and physical aggression. Implications were discussed. Data for this study were collected from the RELATE assessment.