Several self-report measures of conspiracist beliefs have been developed in Western populations, but examination of their psychometric properties outside Europe and North America is limited. This study aimed to examine the psychometric properties of three widely-used measures of conspiracist beliefs in Iran. We translated the Belief in Conspiracy Theory Inventory (BCTI), Conspiracy Mentality Questionnaire (CMQ), and Generic Conspiracist Belief Scale (GCBS) into Persian. Factorial validity was examined using principal-axis factor analysis in a community sample from Tehran, Iran (N = 544). Further, the relationships between scores on these measures and hypothesized antecedents (i.e., education, schizotypal personality, information processing style, superstitious beliefs, religiosity, and political orientation) were examined. Overall, we failed to find support for the parent factor structures of two of the three scales (BCTI and GCBS) and evidence of construct validity for all three scal)