Research on organizational justice has predominantly focused on between-individual differences in average levels of fair treatment experienced by employees. Recently, researchers have also demonstrated the importance of considering dynamic, within-individual fluctuations in fair treatment experienced by employees over time. Drawing on uncertainty management theory, we merge these two streams of research and introduce the concept of justice variability, which captures between-person differences in the stability of fairness over time. Contrary to the intuitive notion that more fairness is always better, our work shows that being treated consistently unfairly can be better for employees than being treated fairly sometimes and unfairly other times. Specifically, in a lab study, variably fair treatment resulted in greater physiological stress than both consistently fair and consistently unfair treatment. In a multi-level, experience-sampling field study, we replicated the positive association between justice variability and stress, and we also showed that justice variability exacerbated the positive, daily relationship between general workplace uncertainty and stress. Moreover, daily stress mediated the effects of justice variability on daily job dissatisfaction and emotional exhaustion. Finally, we showed that supervisors with more self-control tended to be less variable in their fair treatment over time.