The aim of this study was to gather ‘building blocks’ for activities in teacher education programs for teaching in multicultural classrooms. We investigated students’ and teachers’ perceptions of teachers’ interpersonal behaviour in Dutch multicultural classes, the relationships between students’ ethnic and socio-cultural background and their perception of the learning environment, and teachers’ cognitions regarding interpersonal behaviour in multicultural classrooms. Data were collected from 15 Dutch secondary education teachers and their classes. Results showed that culturally related differences in students’ perceptions and teachers using a variety of strategies and knowledge in teaching multicultural classes. Results on teacher knowledge about teaching strategies for multicultural classrooms confirmed indications in the literature on general effective teaching competencies as well as previously found effective teaching methods in multicultural classes.