The media are an important part of young people's lives, but television, computer games, Internet use, cellular phone use, and even book reading threaten healthy sleep. Adults do not fully comprehend the ways in which young people use various media. Media use is a type of behavior that may displace sleep time or shorten it. Media content may lead to overexcitement or cause recurring nightmares. The cellular telephone is a particular threat. Parents may also use media excessively, establishing an unhealthy environment that may lead to sleep dysfunction in children and adolescents. Therefore, anticipatory guidance for healthy behavioral changes should be focused on the family.