In recent years young people use social networks every day. Their massive use significantly affects young people and their psychological development and therefore the focus of this work are young people from 15 to 30 years of age. The aim of the paper is to see the impact of the use of social networks on the mental health of young people. A review of a number of foreign and domestic research has shown that the impact of social networks has a good and bad side. The positive influence of social networks manifests as a higher level of social interaction, building social capital, greater social support and better family relationships. On the other side, the social comparison and the high level of social network engagement can damage self-esteem and lead to depression, as the frequency of use can harm the sleep rhythm, lead to less academic success and harm overall health. Cases of more frequent and more frequent use of social networks can lead to addiction to these, and young people are exposed to violence, most often by peers, which also negatively affects mental health. The inconsistency of the results of different researches has shown that it is essential to focus on certain activities on social networks rather than on the general use of social networks.