To date, procedural justice research has paid little attention to how people react to procedural discrimination (favoring self vs. favoring other), that is, how people react when they and the others are treated with different procedures. To fill this gap in the procedural justice literature and advance our understanding in this area, the current thesis presents an analysis of how reactions to procedural discrimination are qualified by the group membership and intragroup position (ingroup prototypicality and intragroup status) of the parties involved in intragroup and intergroup contexts. Studies 1 and 2 revealed that in an intergroup context, as group members perceive ingroup bias as legitimate, they react more positively when they are favored over an outgroup member than when an outgroup member is favored over them. In particular, because group members perceive the ingroup authority to be more related to them, their reactions to favoring self as opposed to favoring other procedures are stronger when the authority is an ingroup member than when the authority is an outgroup member. Studies 3 to 5 showed that in an intragroup context, peripheral members, who are highly concerned about group acceptance, perceive a high level of illegitimacy and react particularly negatively when a prototypical member is favored over them. On the other hand, prototypical members paired with a prototypical or peripheral member, and peripheral members paired with another peripheral member react similarly to procedural discrimination whether it favors them or the other group member. Studies 6 and 7 also focused on the intragroup context. These studies revealed that when high status group members are favored over a low status member, if they perceive the status difference as legitimate, they perceive relatively high levels of procedural legitimacy and procedural fairness, and report a relatively low level of negative affect. On the other hand, when low status group members are discriminated against in favor of a high status counterpart, they report a relatively high level of negative affect even if they perceive the status difference as legitimate and think that the favoring other procedure is relatively legitimate and fair. Taken together, the current program of studies reveals that depending on group membership or intragroup position, group members may react differently to favoring self as opposed to favoring other procedures. Furthermore, affective reactions to the procedures may not be consistent with cognitive judgments of the procedures. The research also reveals that the influence of group membership and intragroup position on reactions to procedural discrimination can be conceptualized in terms of sensitivity to procedural information (Proposition 1) and perceived procedural legitimacy (Proposition 2), suggesting that the group-value model (Lind & Tyler, 1988) and the social identity perspective (Tajfel & Turner, 1979; Turner, 1985; Turner et al., 1987; for a review, see Hogg, 2005, 2006) can help explain reactions to procedural discrimination. In conclusion, the current thesis makes significant contribution to the procedural justice literature.