As the past twenty years of justice research have demonstrated, perceiving the workplace as fair is associated with higher levels of organizational commitment, job satisfaction, work-related effort, acceptance of work-related policies and procedures, and decreased absenteeism. However, although not always explicitly stated in theories of fairness, there has been a tacit understanding that justice perceptions are not static, but influenced by a variety of factors. In short, extant justice theories assume there are underlying dynamic elements within the construct, but the measures and previous research examining justice has assessed it as if it were a stable and static perception. The purpose of this research, therefore, was to take the first step to explore and describe the frequency and intensity of injustice perceptions at work and how individuals' affective states and traits influence these perceptions. A snow-ball sample of working individuals from across the United States provided ESM data by responding to palmtop computers at randomly scheduled intervals several times a day for 3 work weeks. Additionally, participants provided event-contingent injustice data when they perceived unfair events during their workday. The results of this examination, as well as the use of experience sampling for the study of dynamic workplace injustice, are discussed.