The aim of this research was to examine the competency of school principals to create an inclusive school culture. In the theoretical part of the paper, the educational inclusion is first defined and explained, and then the relationship of society toward persons with disabilities throughout history is presented - in the medical model, the deficit model, the social model and the human rights model. The concept of inclusion in various international documents and Croatian legislation is presented. Subsequently, the characteristics of an inclusive school and the characteristics of an inclusive school culture are explained. The role of school principals in creating an inclusive school culture is explained, while linking the concept of school leadership to the concept of inclusion. Finally, the competencies of the principals are defined and explained, with an emphasis on competencies for creating an inclusive school culture. The second part of the paper presents the results of empirical research. 162 Croatian primary school principals participated in the survey. An online survey was conducted and, for the purposes of this research, an online questionnaire Competencies of school principals for creating an inclusive school culture was constructed. A factor analysis was conducted to establish that the questionnaire was a one-dimensional measure of competencies for creating an inclusive school culture. The results of the research indicated that principals are generally competent to create an inclusive school culture, with being the most competent in accessibility and availability to students, teachers and parents, and least competent in the knowledge of recent professional literature regarding education of students with disabilities. It was found that the answers of the research participants were statistically significantly different in the variables gender and counties of current employment, and it is learned from the open questions that the principals consider the element of cooperation to be an important element for creating an inclusive school culture. Based on the research findings, it is concluded that principals, in addition to being competent to create an inclusive school culture, use their knowledge, skills and abilities to create an inclusive school culture on a daily basis.