One of the difficulties in social research has been to disentangle the effects of race/ethnicity from social class. In two experimental studies with samples of both students and general population (total N = 416), we analyzed the effect of social class, ethnicity and their interaction on prejudice and discrimination using experimental methods. Social class (High vs. Low) and ethnic group (Roma vs. Non-Roma) were manipulated through a cover story. Study 1 showed a main effect of social class, not of ethnicity, on prejudice and discrimination. In Study 2 the effect of social class was replicated, and the interaction effect was also significant for all dependent variables. Results show that negative effects of social class are higher among Roma than non-Roma. Pooled analyses corroborated these findings. Social class is a predictive factor, especially in interaction with ethnicity and should be considered for predicting and reducing prejudiced attitudes and intergroup behaviors fostering inequality.