This paper reports on the attitudes of 340 government primary principals from New South Wales, Australia, towards the inclusion of students with disruptive behaviours in schools. Principals' attitudes were examined using the Principals and Behaviour Survey (PABS), a new composite measure built upon a foundation of existing validated surveys on attitudes towards the inclusion of students with disabilities. Principal component analysis identified 3 components that were used as variables for correlations with a range of demographic characteristics, such as age, qualifications, experience, school size and location. School size and the number of students with a diagnosed mental health condition in the school had a small relationship with principals' attitudes. From the analysis of data from the emotional response scale, it was found that principals' emotions about inclusion were less positive towards students with disruptive behaviour than towards students with sensory, physical or intellectual disabilities. Overall, principals appeared to hold dichotomous positions in regard to the benefits of inclusion, viewing it as beneficial for students with disruptive behaviour but not for their peers. However, principals who held more positive views were consistently more positive across all measures.