The present study explores the differences in students' epistemological beliefs by gender and socio-economic status (SES). The Epistemological Beliefs Questionnaire (Conley, Pintrich, Vekiri, & Harrison, 2004) was adapted and administered to 1230 seventh grade students. The multivariate analysis of variance (MANOVA) revealed differences in epistemological beliefs among students by gender and SES. While girls had more sophisticated beliefs in justification of knowledge than boys, girls and boys appeared to be similar in their beliefs in the Source/Certainty and Development dimensions. According to the results, students having medium and high SES had more sophisticated beliefs on the Source/Certainty dimensions when compared with low SES group.