Children’s sedentary lifestyle and deficient physical activity, increase the dangers for many kinds of non-communicable diseases. Sedentary lifestyle is often related to the increasing tendency towards the use of new technology, mainly the on-screen games and applications. According to several surveys, the time of exposure to such on-screen activities is considered to be a significant risk factor for children. In the current survey, the relation between physical activity of school aged children and the time of exposure to screens was examined. Fifty children coming from Komotini, aged 7-9 years old, participated in this study. Their height and weight were measured with a stadiometer and a weight scale respectively, while their physical activity was estimated with the pedometer Omron HJ-720 ITE2. The time children spent on screen activities was recorded with a questionnaire which was completed by the children’s parents and was reexamined for the accuracy of the answers through interviewdiscussion with the parents during the completion process. For the data analysis a One Factor Analysis of Variance (ANOVA) was used and the significance level was defined at P<.001. The analysis showed that the children who spent more than 3 hours per day on screen activities, recorded less steps ( < 7500 steps per day ) than those who spent less than 2 hours per day ( P<.001 ). The results indicate a constantly increasing danger; children's game seem to be more and more limited to virtual gaming which takes place on a screen and this could lead to considerable limitation of active gaming. This could probably have dramatic health consequences on the later life of the kids and this should be carefully taken into consideration by the experts.