The main goal of the master’s thesis titled “Online communication of the Croatian Handball Federation“ was to illustrate how social networks can be used for communication of handball clubs and federations, primarily on the example of the Croatian Handball Federation as compared to other handball federations. Social networks and the Internet have experienced global growth over the past decade and they will continue to develop in the future. They have become the main channel of communication between people, for advertising and sharing information. Social networks provide two-way communication and allow communicators and users to get feedback information. There are many networks and they are all different and specific in their own way. Some of them use mostly images, some use mostly words and some of them combine both. Handball federations and clubs must adjust themselves to new ways of communication. They have to learn how to use the advantages of networks in order to become more popular and to attract more users. This specific case shows us how handball federations created their own strategy in communicating with social networks users by giving us an example from the World Championship 2017 held in France. The large number of internet users point to the growing need for further development and improvement of social networks. The Croatian Handball Federation introduced some new features to customer communication back then in France, which resulted in their vast popularity on Facebook, Instagram, Twitter and Youtube. The thesis aimed to show how the Croatian Handball Federation embraced social networks and their advantages in communication. For that purpose I compared Croatian Handball Federation to handball federations from other countries that participated in the mentioned World Championship, as regards their social networks use. Seeing that the federations were not the only ones to use social networks, I also compared two largest Croatian handball clubs and their use of Facebook and Instagram.