Introduction: Down syndrome is the most common chromosomal anomaly and it is accompanied by numerous delays, including motor delays. As their motor development lags behind, children with Down syndrome are slower than their peers, and as result, they often become overweight. The main goal of this research was to examine the relationship between body mass index and age with speed of movement in children with Down syndrome. Participans and methods: 20 children from the Association for Down Syndrome - Rijeka 21 participated in the research, of which 12 were girls and 8 were boys aged 8-14 years. The research used a demographic questionnaire and hand tapping test lasting 15 seconds, in which hand hits on the table were counted. The results obtained were processed using Microsoft Excel 2016 and Statistica (version 13.05.17) Results: Children with a lower body mass index had a higher number of taps on the hand tapping test than children with a higher body mass index. Older children did not achieve better results than younger children. Furthermore, 5 children (25%) were obese, 4 (20%) were overweight, while 11 (55%) were normal weight. 19 (95%) children attended some form of teaching. More than half of the examined children did not engage in physical activity. Most of the children did not have any additional health problems. 12 parents (60%) of children with Down sindrome believed that phsiycal therapy sholud be more available. Conclusion: An increased body mass index is present in children with Down syndrome, and it can be concluded that there is connection between the body mass index and the speed of movement, i.e. a decrease in the speed of movement. It can also be concluded that there is no connection between age and the speed of execution of movements, but for this it is necessary to conduct additional research.