The current study used a dyadic daily diary design to examine the transmission of anger over daily interactions within romantic relationships. The results suggested that, when people feel angry in their relationships, they are more likely to engage in destructive behaviors toward their partners. In turn, the enactment of destructive behaviors tends to be perceived by their partners, which elicits partners’ anger. Hence, these findings suggest that anger can promote a negative interpersonal process in which anger spreads across partners and reinforces itself. Effects were moderated by agreeableness, but not by relationship commitment.