Many theories of trust emphasize that trust is most relevant to behavior in situations involving a conflict of interests. However, it is not clear how trust relates to behavior across situations that differ in the degree of conflicting interest: Does trust matter more when the conflict of interest is small or large According to an interdependence perspective, trust becomes an especially important determinant of behavior in situations involving larger, compared to smaller, degrees of conflicting interests. To examine this perspective, we conducted a meta-analysis involving 212 effect sizes on the relation between trust (both state and dispositional trust in others) and cooperation in social dilemmas-situations that involve varying degrees of conflict between self-interest and collective interest. Results revealed that the positive relation between trust and cooperation is stronger when there is a larger, compared to smaller, degree of conflict. We also examined several other possible moderators of the relation between trust and cooperation. The relation between trust and cooperation was stronger during individual, compared to intergroup, interactions but did not vary as a function of the situation being either a one-shot or repeated interaction. We also find differences across countries in the extent that people condition their own cooperation based on their trust in others. We discuss how the results support an emerging consensus about trust being limited to situations of conflict and address some theoretical and societal implications for our understanding of how and why trust is so important to social interactions and relationships. © 2012 American Psychological Association.