Physical self-efficacy is one of the important factors in the success of performing a motorical activity. In most cases, it has been shown that students who have high physical self-efficacy achieve better results and also enjoy performing certain activities. Enjoyment actually represents pleasure and will when performing physical activity. Physical activity is an important factor in a child's development, which significantly affects in his health. Nowadays, when more and more children are turning to technology, it is important to encourage children to engage in physical activities and at the same time enjoy them. This paper examines the reliability of the Croatian version of the questionnaire for assessing physical self-efficacy and enjoyment of physical activity of young school age children. The research was conducted online, on fourth grade elementary school students in Zadar. The level od physical self- efficacy was assessed on the basis of a pictorial scale of physical self- efficacy and the Croatian version of the PACES questionnaire was used to enjoy physical activity. The reliability of the questionnaire for assessing the enjoyment of physical activity is very high in both measurements (Cronbach's alpha are: 0,91 and 0,89) which indicates good reliability and justified use of the questionnaire in further research. The Cronbach's alpha values of the first and second measurements (0,79 and 0,77) for the physical self- efficacy scale are somewhat lower but still satisfactory and justify further use of the scale for research purposes since the metric characteristics of the scale are good. Also, the results showed that the level of assessment of overall physical self- efficacy in male and female students is moderate and that the level of enjoyment in performing physical activity is high. Regarding gender differences, the results show that female students enjoy physical activity more than male students but these differences are not significant. When assessing physical self- efficacy, female students also show better results than male students, significant differences are shown in the assessment of coordination in the first (ASf=3,22 and ASm=2,70) but also in the second measurement (ASf=3,15 and ASm=2,78) .