Emotional states exert an influence on trust and the reciprocation of trust. The current research found that regret and disappointment, though both negatively valenced, have distinct effects on trust (and trustworthiness). Three experiments showed that regret decreased trust and trustworthiness, whereas disappointment increased them. Regret elicited both lower initial transfers and returns in a trust game. Conversely, disappointment gave rise to both higher initial transfers and returns in the same game. The implications of our results are discussed. The findings once again demonstrate that emotions play a crucial role on decision-making.