While there is an increased interest in describing attitudes of teachers, parents and peers towards students with special educational needs in regular education, there is a lack of knowledge about various variables relating to the attitudes of these three groups. The aims of this study are: (1) to examine which variables relate to the attitudes of teachers (N = 44), parents (N = 508) and peers (N = 1113) towards students with Attention Deficit/Hyperactivity Disorder, Autistic Spectrum Syndrome or a cognitive disability in regular primary education and (2) to examine whether teachers and parents' attitudes affect the attitudes of peers. An attitude survey was used to assess attitudes and data were analysed by means of multilevel analyses. The variables found in this study relating to attitudes can be used as a foundation to develop interventions to change attitudes. (Contains 7 tables.)