The research monography deals with the analysis of the educational process of pupils with mild intellectual disabilities in mainstream schools and the analysis of the role of school special educators in working with pupils with mild intellectual disabilities. Theoretical chapters focus on pupils with mild intellectual disabilities in a heterogeneous class and on special pedagogical support for pupils with mild intellectual disabilities. Empirical chapters formulate research problems, research goals and used methodologies of research surveys. The research analyses data from self-designed questionnaires. The final subchapters contain an evaluation of the established hypotheses, the conclusions of research surveys and recommendations for special pedagogical practice.