The goal of this study was to specify relations between internal working models of attachment (IWM) and conflict management behaviors in a sample of young adults involved in romantic relationships. One hundred forty-five romantic couples were recruited to address this goal. All participants were administered the Adult Attachment Interview (C. George, N. Kaplan, & M. Main, 1996) and observed across 2 experimental conditions designed to simulate waiting room and conflict management contexts. As expected, individual differences in IWM predicted positive and negative conflict management behavior. The IWM of the young women predicted more positive behavior across interactions, whereas the IWM of the young men predicted more negative behavior in the conflict management condition. Individuals who were unresolved regarding loss or trauma and who displayed considerable attachment insecurity were particularly vulnerable to more negative behavior, particularly in terms of exhibiting controlling behavior.