A concise review of the literature on the influence of electronic media on children's health is given. The exposure to different media is estimated with special reference to the situation in Germany. The impact on violence and aggressive behavior, on sexuality, on physical activity, obesity and nutrition, on substance use and abuse and addiction, on anxiety, depression, irregular sleep, and attention deficits, on cognition, language and reading, creativity is discussed. Although some of the results reported are still in question, there is no doubt that television and other electronic media negatively influence children's mental and somatic well-being. They have fundamentally changed the life of children and expose them to a powerful experiment with unpredictable and possibly irreversible outcome.