Research shows that power can lead to prosocial behavior by facilitating the behavioral expression of dispositional prosocial motivation. However, it is not clear how power may facilitate responses to contextual factors that promote prosocial motivation. Integrating Fairness Heuristic Theory and the Situated Focus Theory of Power, we argue that in particular, organization members in lower (vs. higher) hierarchical positions who simultaneously experience a high (vs. low) sense of power respond with prosocial behavior to one important antecedent of prosocial motivation, that is, the enactment of procedural justice. The results from a multisource survey among employees and their leaders from various organizations (Study 1) and an experiment using a public goods dilemma (Study 2) support this prediction.Three subsequent experiments show that this effect is mediated by perceptions of authority trustworthiness. Taken together, this research (a) helps resolve the debate regarding whether power promotes or undermines prosocial behavior, (b) demonstrates that hierarchical position and the sense of power can have very different effects on processes that are vital to the functioning of an organization, and (c) helps solve ambiguity regarding the roles of hierarchical position and power in Fairness Heuristic Theory.Keywords: procedural justice; power; hierarchy; sense of power; prosocial behavior. Power, Procedural Justice, and Prosocial Behavior 3 Many classical philosophers and writers who still heavily influence today's thinking, like Plato, Shakespeare, Machiavelli, and Nietzsche, argued that the power that we possess influences whether we treat others in prosocial ways or not (see e.g. Ng, 1980). It is not surprising then that the relationship between power and our treatment of others has been the focus of much social scientific research (see Galinsky, Rucker, & Magee, 2015;Sturm & Antonakis, 2015;Williams, 2014, for reviews). However, this research has so far not resulted in a clear and coherent picture. For instance, consistent with the traditional proposition that "power corrupts", some studies suggest that a high power position undermines prosocial behavior (e.g., Kipnis, 1972) and yet, other studies suggest that high power may promote such behavior (e.g., Schmid Mast, Jonas, & Hall, 2009). One way by which scholars reconcile these seemingly contradictory findings is by showing that power facilitates acting upon one's goals and motivations (Guinote, 2007a;2008). Studies in this tradition show that power, rather than directly promoting or undermining prosocial behavior, serves as a catalyst by facilitating the expression of chronic, personality-based prosocial motivations in observable behavior (Chen, Lee-Chai, & Bargh, 2001;DeCelles, DeRue, Margolis, & Ceranic, 2012).A point that has received much less attention is that the organizational context in which individuals operate is as relevant an antecedent of prosocial behavior as is personality (Penner, Midili, & Kegelmeyer, 1997). However, it is unclea...