Laboratory-based aversive conditioning studies have reliably induced fear toward an image of an outgroup member by pairing the image with a fear-inducing, aversive stimulus. However, laboratory-based studies have been criticized for being simplistic in comparison to the complexities of the real world. The current study is the first to apply an aversive conditioning framework to explain the formation of intergroup fear and subsequent anxiety toward, and avoidance of, the outgroup outside the laboratory. Two samples recalled details of their first negative encounter with an African American (N = 554) or Muslim (N = 613) individual, respectively. Congruent with learning theory, participants who reported an unpleasant event with an outgroup member reported more fear during the encounter than did those who did not report experiencing an unpleasant event. Additionally, the intensity of unpleasantness during the first encounter indirectly predicted outgroup avoidance, via retrospectively recalled fear and current levels of intergroup anxiety.