In the field of epistemic belief research, more studies on how these beliefs are formed in different cultural contexts are called for. Moreover, there are strong assumptions that teachers' instructional practices are paramount to the development of students' epistemic beliefs. The current study aims at investigating differences between Sweden and Germany in both, and in their relationships. A cross-sectional study was conducted with 4,731 students in Grades 5 through 11. To sum up, latent multi group comparison revealed several differences in the level of students' beliefs and classroom characteristics. Moreover, latent regression analyses showed that the observed classroom characteristics were significant predictors of students' beliefs concerning the justification and development of knowledge, and that the prediction pattern differ between countries.