Human beings are responsive to fairness violations. People reject unfair offers and go out of their way to punish those who behave unfairly. However, little is known regarding when unfair treatment can either help or harm performance. We found that basketball players were more likely to make free throws after being awarded a foul specific to unfair treatment (Study 1). Similarly, hockey players were more likely to score during a penalty shot compared to a shootout (Study 2). A laboratory experiment showed that participants were more accurate at golf putting after a previous attempt had been unfairly nullified (Study 3). However, a final experiment revealed that when the task was more demanding, unfair treatment resulted in worse performance (Study 4). Moreover, this effect was mediated by feelings of anger and frustration. These results suggest that performance is sensitive to perceptions of fairness and justice. Link to final version of article: [http://link.springer.com/article/10.1007/s11031-015-9539-1][1] [1]: http://link.springer.com/article/10.1007/s11031-015-9539-1