Previous studies show the positive impact of contingent reward on satisfaction, but few have examined moderators of this effect. We theorized that interpersonal fairness – treating people with dignity and respect – moderates the contingent reward effect because it creates the situation in which followers can positively engage with contingent reward efforts from their leaders. We therefore examined how interpersonal fairness moderates the contingent reward effect, finding that the positive impact of contingent rewards is stronger as interpersonal fairness increases. The implication of the finding is that using contingent rewards may only be effective when implemented in  polite, respectful manner represented by interpersonal fairness.