Intergroup exchanges are an integral part of social life but are compromised when one group pursues its interests at another group’s expense. The present research investigates whether expressing emotion can mitigate the negative consequences of such actions. We examine how emotions communicated by either an ingroup or outgroup member following an ingroup member’s breach of trust affect other ingroup members’ feelings of guilt and pride, and subsequent allocation of resources. In both studies, groups of participants played a two-round trust game with another group. In round one, they observed a member of their own group failing to reciprocate a trusting move by the outgroup. In Study 1 (N = 85), an outgroup member then communicated anger or disappointment, whereas in Study 2 (N = 164), an ingroup member then communicated happiness or guilt. Comparisons with no-emotion control conditions revealed that expressions of outgroup anger and ingroup guilt increased participants’ allocations to an outgroup member in round two. The effect of an outgroup member’s anger expression was mediated by participants’ diminished feelings of pride about the ingroup action, whereas the effect of an ingroup member’s guilt expression was mediated by participants’ own feelings of guilt. Taken together, these findings support a social appraisal approach and highlight the roles that pride and guilt can play in shaping intergroup resource allocations.