Physical self-efficacy is one of the important components when engaging in some physical activity. How successfully a particular motor task will be performed depends on our own self-confidence and belief that we can do it. Physical activity affects a person's physical and mental growth and development, reduces disease prevention. It is very important to encourage them to engage in some activities from the earliest childhood. Parents and later friends play a very important role in this. This paper examines the relationship between physical self-efficacy and social support of younger school-age students with the level of physical activity. Given the situation caused by the Corona virus, the study was conducted online, on fourth-graders, in two schools in Zadar County. Physical self-efficacy will be assessed by the Croatian version of the Self-efficacy questionnaire, and social support by the Croatian version of the Social support questionnaire. The association of social support and physical self-efficacy with the level of physical activity of students will be determined by the Pearson correlation coefficient. The Cronbach's coefficient of reliability of social support (0.94), as physical self-efficacy (0.92) was calculated, which shows good reliability and justified application of the questionnaire. Also, the results showed that the association of social support with the level of physical activity is significant. Students have a higher level of physical activity the higher the social support. Likewise, the association of physical activity with physical self-efficacy is also very significant. The higher the level of physical activity, the more physical self-efficacy students have. Regarding gender differences, female students assessed their physical self-efficacy as well as social support by a smaller proportion of male students, but looking at the number of male and female students we see that there are no statistically significant differences.