The aim of the three different studies presented was the development and evaluation of the Differentiated Attitudes Towards Inclusion Scale as a valid, reliable and economic instrument for the measurement of teachers' attitudes towards the inclusion of students with certain special educational needs (SEN). In a sample of student teachers, exploratory factor analyses on the versions of the questionnaire with focus on Learning Disabilities (LD) and Emotional and Behavioural Disturbances (EBD), respectively, indicated four first-order factors. These factors represent attitudes concerning the social and academic impact of inclusive education on students with and without SEN. They can be combined in a higher-order model with one general second order factor. Using confirmatory factor analyses, this factorial structure was replicated in another student teacher sample and in a sample of primary and secondary school teachers. Furthermore, attitudes towards the inclusion of students with EBD were significantly more negative than those towards the inclusion of students with LD. The findings emphasise the need to distinguish between certain SEN when measuring teachers' attitudes towards inclusion. Potential applications of the new measure are discussed.