Social networks are an inevitable part of everyday life, for both adults and adolescents. They allow users to interact with others through messages, posting photos, videos, etc. It enhances mutual connectivity of users based on common interests. Social networks have many advantages but also disadvantages. Adolescents are the most frequent user group of users, and that period of their lives may be subject to various influences. Therefore, this paper examined the connection between the use of social networks and self-esteem of adolescents in the area of city Rijeka. The basic objectives of this paper were to identify differences in the use of social networks and self-esteem of adolescents in the area of city Rijeka considering gender, type of school (elementary, secondary vocational school or gymnasium), number of friends / followers on social networks and the amount of time spent on social networks, and to establish the connection between the use of social networks and the self-esteem of adolescents in the city of Rijeka considering the intensity of social networks` use, the feelings of adolescents about themselves about using social networks and their own opinion about their popularity. The survey involved 119 adolescents from elementary, secondary vocational schools and gymnasiums in the area of city Rijeka. The research results showed that the use of social networks has more positive connotations than negative ones. Moreover, adolescents who spend more time on social networks and have a greater number of followers express a higher level of well-being and self-esteem, which is very important for this turbulent period of life. However, it should be emphasized that among many variables, however, there was no connection. At the end of this paper certain conclusions and recommendations for future research are presented. Likewise, the role of pedagogues in the awareness of adolescents on this topic is emphasized as well as the need for conducting further research.