During last 20 years, many experts, but also some public figures have noticed the increasing number of children and youth that exaggerate with the use of Internet. There are more and more cases in which this is above all limits, it becomes an addiction. Those symptoms are not much more different than the symptoms of „classical addicts”, especially those addicted to cocaine, heroine or gambling. Main consequences are: neglecting their school responsibilities, isolation from their peers, but also some physical consequences such as insomnia, problems with eyes or pain in their back. What is concerning is the fact that this develops at a very young age, when children start developing their own attitudes and their identity. There are many addictions to Internet, among which dominate: addiction to social networks, pornography and videogames. The main figures in this prevention are parents, teachers and the media. In Croatia, treatment of this disorder is conducted in special institutions or department of psychological clinics.