Purpose <p>Intimate partner aggression (IPA) is a prevalent public health concern that is tied to numerous negative consequences. Thus, it is critical to delineate factors that can be targeted in interventions. Guided by intra- and interpersonal models of aggression, the present study aimed to examine associations between couples’ ratings of their own and their partners’ negative and positive emotions, differences between emotional self- and partner-ratings, and psychological and physical IPA perpetration.</p> Method <p>Sixty-seven community couples (<i>N</i> = 134 individuals) in largely bidirectionally aggressive relationships provided data on their own emotions, their perceptions of their partners’ emotions, and IPA via an online self-report questionnaire.</p> Results <p>Actor Partner Interdependence Models showed that more extreme emotions, independent of their valence, were associated with greater harm, such that both higher negative and higher positive emotional ratings related to higher risk for IPA perpetration by both partners. Moreover, individuals’ ratings of their partners’ emotions showed more consistent effects than self-ratings, underscoring the interpersonal nature of IPA. Lastly, female partners’ ratings of their male partners’ emotions were especially impactful.</p> Conclusions <p>These findings replicate and extend prior research and highlight that individuals’ interpretations of their partners’ emotions may be useful in predicting IPA perpetration. Prevention and intervention programs for bidirectionally aggressive couples may benefit from targeting inaccurate partner perceptions via dyadic approaches to decrease the risk of IPA.</p>