This article investigates the relationship between the achievement level of students in classes and the presence of students identified as having special needs in inclusive settings. In particular, it examines whether the presence of students with special educational needs in inclusive classrooms has an effect on the national mathematics standards achievement of their fellow students. In order to do so, the national standard scores of approximately 75,000 fourth graders in mathematics were used as dependent variable in multi-level regression modelling. As independent variables at class level the number of students with special needs and at the individual level socio-economic, cultural and ethnic background variables were used together with gender and age. Results show only a very small effect of the presence of students with special needs on the national mathematics standard scores of their classmates. The effect can be either positive or negative depending on further class conditions.