The research was motivated by the growing importance of social media in the marketing of the National Tourism Organizations (NTO). The NTOs of the top ten most successful countries according to the number of international tourists in 2016 were selected as a research sample for analysis of the way, intensity and effectivity of the social media use in the destination marketing. The social media selected for above-mentioned analyses were Facebook, YouTube, Twitter, Flickr, Instagram, Pinterest, Google+ and Snapchat. The data collected for the analysis were publicly available data found on the NTO websites and in their social media accounts. The quantitative features of these NTO accounts (number of fans, number of their contributions, number of subscribers' responses), their management (especially the response to user contributions and inclusion of users of generated content) and the concept and focus of contributions generated by the NTO were evaluated and mutually compared. The analysis of the social media use by the NTOs of the ten selected countries has pointed out the importance of the social media role in their destination marketing. The selected NTOs use predominantly Facebook, YouTube, Twitter, and Instagram accounts, but only a few of them perform high quality management of these accounts. British, Italian and Mexican NTOs use the social media most, while Thailand and Turkey NTOs use them least. In addition to YouTube and Facebook, Instagram has shown a great potential for the systematic destination marketing exercised by the NTOs, as it has a signifi cant advantage over still yet dominant Facebook in the posting view for all subscribers.