The growth of media has had an ever-expanding role in the lives of children, especially in terms of a child's physical and mental health. Here, Michael Rich, MD, MPH, director of the Center on Media and Child Health at Children's Hospital Boston, comments on media as a force that powerfully affects child development, health, and behavior. Paying particular attention to TV, movies, music, and video games, Rich offers perspective on common concerns over media and suggests ways to avoid the media's negative effects.