It is often reported in the existing literature, that there is a positive influence of physical activity on physical and mental health and many studies indicated, that this positive association is already shown in the early childhood. At the same time there are results, which imply that children?s lifestyle is characterized by increased physical inactivity and that health-promoting amount of physical activity is not achieved. Moreover some studies reported about an at least weak correlation between physical activity and anxiety. Fears and worries are very common in prepubertal children, so the question that arises is, if physical activity can prevent anxiety in childhood. 25 girls and 26 boys in the age between 8 and 10 years (M = 8.57, SD = 0.72) took part in the present study. The amount of physical activity was captured over the period of 6 days by an accelerometer. To inquire the anxiety the KAT-2 was applied. Both boys and girls showed a low level of physical activity. Boys spent more time in the health-promoting activity category of high intensity than girls. In contrast girls showed a trend for a greater amount of inactivity. There was no sex difference relating to anxiety. A relation between physical activity and the amount of anxiety couldn?t be observed. In the present study primary school-age children showed a low level of physical activity, whereas girls were more affected than boys. Furthermore the results imply, that physical activity doesn?t prevent anxiety at primary school age. Follow-up studies are necessary, because of some limitations relating to the size of the sample.