The current study sought to examine the association between the level of general trust and the judgment accuracy of others’ cooperativeness. Based on data collected from 107 female first-year undergraduate students, we demonstrated that a high level of general trust was associated with a high level of judgment accuracy of group members’ cooperation in a social dilemma game. Additional analysis suggested that the association was present even when the judgment accuracy was divided into hit rate (i.e., the rate of correct judgment on the cooperator as a cooperative) and correct rejection rate (i.e., the rate of correct judgment on the non-cooperator as a non-cooperative) by controlling the participants’ judgment bias, Big Five personality traits, and the proportion of cooperators in the group. These results are in accordance with previous studies insofar as they suggest that high trusters are more skilled at discerning others’ trustworthiness. The current study adds to the evidence that high trusters have increased cognitive skills and supports Yamagishi’s emancipation theory of trust.