Focusing on the dominant group’s (Sunni-Turks) attitudes towards the largest ethnic and religious minorities (Kurds and Alevis, respectively) in the Turkish social landscape, this study investigates the determining factors of ethnic and religious prejudices in intergroup relations. The study draws several hypotheses about out-group rejection from social identity and ethnic competition theories and tests them utilizing new, original public opinion survey data. The empirical findings confirm the presence of a substantial degree of ethnic and religious prejudices in the Turkish social setting. Furthermore, statistical analyses show that unlike economic factors, political and cultural variables, such as ideological orientations, nationalist tendencies, and religiosity, perform much better in terms of predicting Sunni-Turks’ exclusionary attitudes towards ethnic and religious out-group members. Thus, intergroup prejudice or intolerance in the Turkish setting is deeply ingrained in cultural and political divisions rather than in economic factors. The study also discusses some major theoretical and practical implications of the empirical findings.