This article investigates the impact of trust on bribery. We measure trust with a survey question from the World Values Survey on whether respondents think others would take advantage of them if given the chance, and we observe bribery behavior in an experimental bribery game. The research was conducted in China and Italy, which have relatively high perceived-corruption levels, as well as in Japan and the Netherlands, which have relatively low perceived-corruption levels. In the bribery game, participants have the opportunity to bribe another participant to cheat to their advantage. We hypothesized that honoring bribing agreements depends on trust, the endorsement of such agreements is independent of trust. We find evidence that trust enables bribery in the two low-corruption countries, but no evidence that trust enables bribery in the two high-corruption countries. More specifically, trust predicts bribers' trustworthiness in honoring the bribery agreement once they enter into one. The results reveal a dark side of trust: It supports socially detrimental cooperation when a deal is unenforceable.