Intergroup dialogue provides what students need in order to relate and collaborate across differences, something they have to do in community projects that usually involve interactions across racial, social class, religious, and geographical divides. In this article, the authors demonstrate the efficacy of intergroup dialogue, drawing from a multi-university study involving fifty-two parallel field experiments in which students were randomly assigned either to dialogue courses or to control groups. The results show that, as compared with the control groups, the dialogue students experienced greater increases in their understanding of race, gender, and income inequality; their intergroup empathy and motivation to bridge differences; and their commitment to postcollege social and political action. Moreover, they also experienced greater increases in the efficacy and frequency of their intergroup action during college, as well as in their cognitive openness and positivity in intergroup situations.