Research shows that the inclusion of women in negotiations and conflict resolution efforts contributes to peaceful solutions to disputes and armed conflict. Yet we know little about how women contribute to peacebuilding. What, specifically, are women doing to help produce more peaceful outcomes? We present evidence from an international bargaining experiment showing that women contribute to peace by seeking more equitable and symmetrical solutions, even if these provide lower material payoffs. Critically, however, women are willing to give up on asymmetric advantage only when they negotiate with other women. The gender composition of negotiation dyads also significantly influences the duration of negotiations. Statistical analysis of historical territorial disputes probes the external validity of these results, offering suggestive complementary evidence. The main policy implication of our findings is that bilateral disputes will be settled more efficiently and equitably when both sides are represented by women. Our findings should encourage scholars to develop dyadic, not monadic, models of how gender affects international negotiations.