New “idols” having impact on opinion formation of children and adolescents are new technologies Internet, mobile phones and social networks. The aim of this paper is to research the impact of modern technologies on children and adolescents, their attitudes and habits related to modern technologies. The research was carried out by a single survey method using a questionnaire survey anonymously on the total sample of 375 students at the age between 10 and 17 years, out of which 220 test persons were students of the fifth up to the eight grade in elementary schools and 155 t est persons from the first up to the third grade in high schools. The results suggested that students perceive themselves as successful Internet users who use the Internet on a daily basis most frequently on their mobile phones or computers in the house, for entertainment purposes or to communicate electronically. Students are connected by numerous social networks of which the YouTube and Instagram account for the biggest share; they are mostly driven by the feeling of boredom. Most students think it is easier to communicate by a social network. About a quarter of all students spend their free time engaged in modern technologies. Conclusion: about one half of the students cannot imagine the life without modern technologies any more, which implies a need for educating children and adolescents about useful and potentially harmful effects of modern technologies, also parents and teachers as well as other professional workers involved in care of children and adolescents.