Social Network Sites (SNSs) are popular social media platforms. They have been around for more than a decade and drastically changed the word of internet and the methods of communication. Nowadays, they are widely considered to be quite influential, due to their impact on the way people interact with one another. Users exchange messages, information, and photos, revealing parts of their character and behaviour. As the use of SNSs has been expanded and users are increasing, the present study aims to explore the factors affecting the intention to use SNSs. A research model was created, in order to examine the relationship between 18 factors, categorized into five different dimensions (Social interaction, Social networking features, Sentiment factors, Peer influence, Information related factors), and intention to use SNSs. The proposed conceptual framework was tested, using a newly-developed structured questionnaire, in a sample of 671 social network users, members of Generation Z (people born after 1995). The Structural Equation Modelling (SEM) technique was used in order to test the research hypotheses. “Sentiment factors” and “Peer influence” were found to be the most important significant determinants of the actual use of Social Network Sites (SNSs).