Significant reduction in physical activity together with increasing body mass and obesity is increasing more and more lately. Particular prevalence data is especially worrying when it comes to children. The main goal of the research was to determine the level of physical activity of the primary school children, as well as their nutritional status, and the association between these two, accompanied by the further analysis of the data concerning their nutritional status, physical activity and sedentary behaviour. The studens from the first to eight grade of the primary school Bijelo Brdo were the participants of the research. The level of the physical activity was estimated with the help of the PAQ-C questionnaire, while the nutritional status was estimated using body mass index (BMI). In order to calculate gender differences or differences based on the grades (lower vs higher), T-test for the independent samples, Mann Whitney U test, Chi-squared test were used. For determining the association between the indicators of the nutritional statuse and the level of the physical activity, Spearman's rank correlation coefficient was used. The results showed that the boys had a higher level of the physical activity than the girls, while at the same time, it wasn't completely possible to determine if they were less sedentary than the girls. The difference for the overall level of the physical activity between lower and higher grades couldn't be determined. It was determined that the higher grades students watched television more on the weekdays. Even though this research didn't confirm the correlation between the nutrition status and the level of the physical activity, the fact that physical activity needs to be present in a life of children as well as adults cannot be neglected because it is good for their physical and mental health.