The main issue of this article is inclusive education for pupils with special educational needs (SEN). Inclusion in our study focuses on three core areas: the role of the school leaders, the role of teachers and the practice of curriculum planning. The results are based on interviews with school leaders and teachers in Norwegian primary and lower secondary schools. We find that most of the teachers are working and planning on their own and seldom collaborate with or support each other. At one of the schools, however, we see a clear tendency for roles and practices that are based on collaboration and joint efforts. The same pattern is also found in the school leaders' focus on strategies in their efforts to realise inclusive education for pupils with SEN. Consequently, the analysis shows a clear and systematic correlation between the results in the three core areas. The roles of school leaders and teachers and the curriculum planning practices differs widely between schools, and seem to be part of school cultures characterized by predominantly individualistic or collaborative approaches in their work on inclusion.