Physical activity during childhood and adolescence has numerous health benefits, while sedentary behavior, especially electronic media use, is associated with the development of overweight. Therefore, the promotion of physical activity during childhood and adolescence is an integral part of national public health efforts. The aim of this article is to describe the physical activity behavior of German children and adolescents based on the nationwide data of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS wave 1). Furthermore, the association between physical activity and sports participation and use of screen-based media in youth aged 11 to 17 years was analyzed. The analyses included data from 10,426 children and adolescents aged 3-17 years collected by telephone interviews. Children older than 11 years answered the questions by themselves, whereas a parent was interviewed for younger children. The descriptive analyses were performed under consideration of social and demographic factors. According to the results of KiGGS wave 1 a total of 77.5% (95% Cl 76.0-78.9 %) of the children and adolescents participated in sports activities, and 59.7% (58.1-61.3 %) were members of a sports club. The recommendation of the World Health Organization (WHO) to be physically active at least 60 min per day was achieved by 27.5% (26.0-28.9 %). Children and adolescents with a low socioeconomic status (SES) participated less in sports activities than children of higher SES groups. Excessive use of screen-based media was more likely to be associated with lack of sports participation than with a lack of physical activity. In the future, preventive measures should promote the daily physical activity of children and adolescents and additionally encourage children and adolescents with low SES to participate in sports activities.