Taking into account the psychophysical development of a young person, a child in particular, attention should be paid to forming certain habits related to physical activity, health, nutrition, hygiene, and aesthetics during the preschool period as such habits will be of utmost importance in his/ her adult life. Physical activity of children affects various health parameters both today and in the future. Specialists draw attention to the correlation between physical activity and the development of the musculoskeletal system, body posture, the nervous, respiratory and vegetative systems. The lack of physical activity may result in cardiovascular diseases or obesity. These are just some of the reasons for which people need physical activity in their lives. Bearing in mind the lack of research on this issue, it was decided to conduct research on the physical activity of children (210 students) aged 4-6 attending selected kindergartens located in the town of Biala Podlaska, Poland. The level of physical activity of children was measured with the use of special devices, so called actigraph units (accelerometers in Polish). Due to a small size of this wrist-watch-like device, movements of children or their participation in games and different forms of activities in kindergarten were not hampered. On the basis of the collected data, statistical analysis was performed. Non-parametric statistical tests were used in order to identify the relationship between variables of the physical activity level and sex, age and weight of a child. Data analysis revealed statistically significant differences between the level of physical activity and some personal characteristics. The research conclusions, which will be helpful in providing effective education in the field of physical activity, were made available to kindergartens.