The main prerequisites of a successful specialist treatment of children with intellectual disability are knowledge of the dynamics of ability development, assessment of a child's achieved developmental level and how it affects the child's everyday functioning. The aim of this paper is to systematically present a conceptual frame, program, and content of extracurricular activities conducted by intellectual disability specialists who work with children with intellectual disability at primary schools. It includes the goals, outcomes, contents, ways of implementing and evaluating the work program of intellectual disability specialists at primary schools in the fields of cognitive abilities, adaptive skills, non-verbal communication, and application of psychomotor reeducation. The application of specific fields and treatment procedure depend on age, strengths and weaknesses of every child, and environmental requirements. For a treatment to serve its purpose, it is necessary that all its contents be adapted to circumstances, expectations, and functional barriers of the natural surroundings, and applicable to the process of education, training, interpersonal communication and other contents of everyday life.