In Sweden, teachers in mainstream schools show frustration and insecurity about how to organise education for inclusion and diversity. This article contributes to the understanding of how they articulate their view of the advantages and disadvantages of including students with EBD in mainstream classes. To study teachers' understanding, an approach of discourse theory which takes inspiration from Laclau and Mouffe (1985. "Hegemony and Socialist Strategy." London: Verso) was applied. The empirical material consisted of 6 focus group interviews and 37 individual interviews based on stimulus texts. According to the results, the prevailing discourses focused on the disadvantages of it. However, they were articulated differently and filled with meaning mainly by three recurring nodal points: (1) problems, (2) dilemmas and (3) impossibility. The advantages of including students with EBD in mainstream classes were only to be found in the antagonistic discourses. They were articulated in different ways but were overpowered by others and therefore failed to fix the meaning. The overall conclusion is that teachers base their understanding on both their experiences and on the policy of the Educational Act, but the pragmatic discourse of the disadvantages was hegemonic to the ideological antagonistic discourse of the advantages.