Development of information and communication technologies and social networks is a phenomenon of 21st century that has affected the whole world and transferred face to face communication into a digital form. New generations of current adolescents are the first ones that have grown up with social networks, which make their childhoods different in comparison with other generations. A lot of previous researches have shown that adolescents spend a lot of free time on the internet and social networks, and the ways they do it can be constructive or destructive. The destructive ways of using the internet and social networks are in the focus of numerous researchers who tried to find answers about risk behaviours on the internet and reasons for their appearance. This paper is focused on studying correlations between risk behaviours on social networks and environmental factors related to significant people in adolescents’ lives (parenting styles and peer pressure, both regarding online behaviours). This research was conducted in June 2019, using a self-description questionnaire, with a sample of 74 students of one secondary school. Obtained results have pointed to the existence of correlations between risk behaviours on social networks and the peer pressure to engage in such behaviours, but haven't proven the existence of correlations between risk behaviours on social networks and parenting styles. Besides that, other results that are not directly tied to the problems of this research but can be significant for this topic, are presented.