In Flanders, the number of pupils in special education is higher than the European average. In order to further improve inclusion rates in regular education, the focus of this paper explores the relationship between personality traits, attitudes and self-efficacy. This opens the door to a better understanding of the determinants of inclusive behaviour towards pupils with disabilities. The current study has a quantitative design in which attitudes were measured on the basis of the ATDPO, self-efficacy was measured by a self-constructed item and personality traits were measured by the TIPI. A significant small correlation was found between (1) attitudes, self-efficacy and the personality trait “agreeableness” and (2) self-efficacy and the trait “openness to new experiences”. Since personality traits precede an individual’s attitudes and self-efficacy, it is important that teacher training programmes encourages and actively express these values in order to positively influence attitudes and self-efficacy.