Based on two large-scale studies from Germany, we examined how different types of teachers' cultural beliefs are related to immigrant students' school adaptation. Specifically, we investigated the relationship of teachers' multicultural beliefs appreciating cultural diversity, their egalitarian beliefs focusing on all students' similarities and their assimilationist beliefs that immigrant students should conform to the mainstream context with immigrant students' academic achievement and psychological school adjustment as indicators of their school adaptation. We also explored all of these associations for non-immigrant students. Study 1 used data on the multicultural, egalitarian, and assimilationist beliefs of German language (N[subscript Teachers] = 220) and mathematics (N[subscript Teachers] = 245) teachers and on students' achievement and feelings of helplessness in German language classes (N[subscript Students] = 2606) and mathematics classes (N[subscript Students] = 2851) as well as students' school satisfaction. Study 2 analyzed data on teachers' multicultural and egalitarian beliefs (N[subscript Teachers] = 456) and students' achievement and self-concept in mathematics (N[subscript Students] = 4722). Overall, multilevel analyses revealed no relationship between teachers' cultural beliefs and any of the indicators of immigrant and non-immigrant students' school adaptation. These findings challenge the notion that overall, teachers' cultural beliefs effectively translate into students' school adaptation.