Across two studies, we provide evidence for group-based trust in strangers. Specifically, when we offered participants a choice between an unknown monetary allocation made by an in-group (university or major) or an out-group allocator, both of whom had total control over the distribution of an identical sum of money, participants strongly preferred the in-group allocator. This preference occurred regardless of whether the stereotype of the in-group was relatively more positive or more negative than that of the out-group. However, this preference did not persist when participants believed that the allocator was unaware of their group membership. Measures of expected share of the allocator's funds support our hypothesis that differential trust of in-group members results from expectations of altruistic and fair behavior toward fellow in-group members rather than from positive stereotypes of the in-group.