On the basis of fairness heuristic theory, it is argued in this article that people especially need fairness when they are reminded about aspects of their lives that make them uncertain. It is therefore proposed that thinking about uncertainty should make fairness a more important issue to people. The findings of 3 experiments support this line of reasoning: Asking (vs. not asking) participants 2 questions that solicited their thoughts and feelings of being uncertain led to stronger effects of perceived procedural fairness on participants' affective reactions toward the way they were treated. It is argued that these findings suggest that fairness matters to people especially when they are trying to deal with things that make them uncertain. An implication of the current findings therefore may be that fairness is important to people because it gives them an opportunity to manage uncertain aspects of their lives.