Although negotiation research is thriving, it has been criticized as having an arelational bias—emphasizing autonomy, competition, and rationality over interdependence, cooperation, and relationality. In this article, we advance a new model of relationality in negotiation. Drawing on research in social psychology, we describe the construct of relational self-construals (RSC) and present a temporal model of RSC and negotiation. After delineating the conditions through which RSC becomes accessible in negotiation and conditions that inhibit its use, we discuss how RSC affects negotiators' pre-negotiation psychological states, early and later tactics, and negotiation outcomes. We illustrate a number of distinct relational dynamics that can occur based on the dyadic composition of RSC, each of which brings distinct benefits and costs to the negotiation table. Implications for the science and practice of negotiation are discussed.