Physical activity plays a key role in the development of primary school-age children, encouraging their physical, emotional and cognitive progress. When it comes to children with developmental disabilities, physical activity plays an equally important role. Adapted physical activities can significantly improve motor skills, coordination and balance in children with special needs. Integrating children with developmental disabilities into physical activities also promotes inclusion and acceptance among peers, which is crucial for their overall development and integration into society. The main goal of this paper was to gather and present the impact of physical activity on the development of elementary school-age children with developmental disabilities through a systematic literature review. In the review of the available literature, two databases were used: PubMed and Scopus. The keywords used in the literature search were: "exercise*" OR "physical activit*", "child*" OR "pupil*", and "developmental disorder*" OR "difficult*" OR "disabilit*". A total of 2251 works were collected, which was followed by a more detailed review of the works according to inclusion and exclusion criteria. 15 papers met all criteria and were later included in the final analysis. In accordance with the main goal, the positive impact of physical activity on the overall development of children with disabilities was determined. The best results were recorded with music therapy and interventions in water, while the least effect on the overall development was the training of adapted takwondo. Considering the available data, a larger number of works and a larger number of respondents are needed to investigate additional development possibilities within the population of elementary school children with difficulties.