This study examined the impact of induced mood and fairness on the categorization of Organizational Citizenship Behaviors (OCBs). Positive mood and perceptions of fair job conditions were predicted to lead to broader categorization of job tasks. Mood, procedural, and distributive justice were manipulated. Participants in a positive mood were more likely than were participants in a negative mood to label extra-role job tasks as in-role. This supports the notion that employees in a positive mood may inadvertently engage in OCBs because such behaviors are perceived to be part of the job. No differences in categorization were found between positive and neutral mood conditions, indicating that participants in the negative condition were more narrow in categorization breadth than were those in the positive condition in distinguishing in-role behaviors from extra-role behaviors.