Purpose: review of domestic and foreign studies in the field of Internet addiction. Materials and methods. A review of the literature is presented and scientific studies on the prevalence of Internet addiction according to researchers from various countries are analyzed. The authors conducted a scientific search using the relevant keywords in the PubMed and Google Scholar search engines, in the Scopus, Web of Science, MedLine, The Cochrane Library, EMBASE, Global Health, CyberLeninka, RSCI (eLIBRARY.RU) and others databases. Results. Internet addiction is widespread among children, adolescents and adolescents, and every year their number is increasing. In most of the studies conducted to identify internet addiction, the most accessible research methods were used – questionnaires, questionnaires. Individuals of early adolescence who are prone to Internet addiction have anxiety-depressive states, difficulties in doing work, and high excitability. Conclusion. The results of studies of Internet addiction conducted in different countries of the world prove that this phenomenon has a worldwide prevalence and currently there are questions about the nosological affiliation, diagnostic criteria, clinical manifestations, and especially the prevention of Internet addiction.