Objective: Previous research has demonstrated a significant association between trauma and intimate partner aggression (IPA) perpetration. However, the precise mechanisms underlying this relationship have yet to be fully elucidated. In the present study, we examined the impact of several key factors implicated in Ehlers and Clark’s (2000) cognitive model of trauma (i.e., trauma cognitions, anger, hostility, and rumination) on IPA perpetration. Method: Participants in this study were 271 male and female heavy drinkers at high risk for IPA from the community who completed measures of dysfunctional posttraumatic cognitions, dispositional rumination, trait anger and hostility, and IPA perpetration. A moderated mediational model was tested to determine how these variables interact to predict IPA perpetration. Results: Results indicated that anger and hostility mediated the effect of negative cognitions about the world on IPA perpetration, with this indirect effect being stronger for individuals with higher levels of rumination. Conclusion: These findings suggest that cognitive and affective processes that may result from trauma exposure are associated with IPA and should be targeted in prevention and intervention programs for individuals at risk for perpetration. (PsycINFO Database Record (c) 2017 APA, all rights reserved)