The harmfulness of anti-Semitic beliefs is widely discussed in current political and legal debates (e.g., Cutler v. Dorn). At the same time, empirical studies of the psychological consequences of such beliefs are scarce. The present research is an attempt to explore the structure of contemporary anti-Semitic beliefs in Poland—and to evaluate their predictive role in discriminatory intentions and behavior targeting Jews. Another aim was to determine dispositional, situational, and identity correlates of different forms of anti-Semitic beliefs and behavior. Study 1, performed on a nation-wide representative sample of Polish adults (N = 979), suggests a three-factorial structure of anti-Semitic beliefs, consisting of: (1) belief in Jewish conspiracy, (2) traditional religious anti-Judaic beliefs, and (3) secondary anti-Semitic beliefs, focusing on Holocaust commemoration. Of these three beliefs, belief in Jewish conspiracy was the closest antecedent of anti-Semitic behavioral intentions. Study 2 (N = 600 Internet users in Poland) confirmed the three-factor structure of anti-Semitic beliefs and proved that these beliefs explain actual behavior toward Jews in monetary donations. Both studies show that anti-Semitic beliefs are related to authoritarian personality characteristics, victimhood-based social identity, and relative deprivation.