ABSTRACT We examined the consequences of witnessing interparental psychological aggression in childhood for daily conflict processes in adult intimate relationships. Both partners in 73 heterosexual couples provided daily diary reports of relationship conflict over a 28-day period. Partners' reports of witnessing mother-to-father and father-to-mother psychological aggression were used to predict exposure to daily relationship conflicts and reactivity to those conflicts (as reflected in end-of-day anger). Results showed no evidence of exposure effects: Witnessing interparental psychological aggression was unrelated to the number of conflict days reported by either partner. Reactivity effects emerged for males only, with father's aggression predicting increased reactivity and mother's aggression predicting the opposite. However, we found evidence of direct or unmediated effects of interparental conflict on daily anger for both males and females. Mirroring the reactivity pattern, the same-sex parent's psychological aggression predicted greater daily anger, whereas the opposite-sex parent's aggression predicted less daily anger. These effects emerged independently of Big Five measures of personality; moreover, Big Five measures did not predict outcomes independently of interparental aggression.