Intellectual disability is a dynamic developmental disorder with unknown etiology, clinical course and prognosis that refers to non-specific disorders in intellectual development, which include impairment of brain and central nervous system function and appear up to 18 years of age. People with intellectual disabilities are prone to a sedentary lifestyle, a reduced level of physical activity and the development of chronic diseases at an earlier age than people without intellectual disabilities.Numerous studies have shown the positive effects of physical activity and sports on physical fitness. Physical fitness is measured by various objective, reliable and valid tests, and is divided into factors related to health and those related to physical skills. The aim of this study was to investigate the effect of physical activity and sports on the physical fitness of adults with intellectual disabilities. The research question is define using the PICO method, and search engines and platforms PubMed, Google Scholar and Web of Science were examined. Inclusion and exclusion criteria were: studies published from 2018 to 2023, availability of full texts, Bosnian, English, Croatian and Serbian languages of study, studies published in MEDLINE and Web of Science Core Collection databases, studies with objective methods of outcome measurement before and after the intervention and study with a sample of adults with intellectual disabilities over the age of 18. After excluding all duplicates and studies that did not meet the inclusion criteria, from the initial 94 studies, only 3 recent studies were included in the further analysis. In all three studies, people with intellectual disabilities carried out a specific exercise program, and their physical fitness was measured with objective tests before and after the intervention. Two studies were randomized control trials and one study with one group of subjects. In all three studies, there was statistically significant improvement after the intervention in almost all tests that measured physical fitness, which is why it can be concluded that the effect of physical activity and sports on the physical fitness of adults with intellectual disabilities is very positive, thus confirming all hypotheses defined in this thesis. Given the small number of relevant studies included in this paper, further research into the effect of physical activity and sports on people with intellectual disabilities is needed.