The paper analyzes how some of the most important libraries in Romania (The National Library of Romania, the Academy Library, the „Carol I� Central University Library in Bucharest, the „Lucian Blaga� Central University Library in Cluj, the „Eugen Todoran� Central University Library in Timisoara and the „Mihai Eminescu� Central University Library in Iași) and, for comparison, two major UK libraries (British Library and Oxford University Library) uses social media platforms. To perform this analysis are presented the library role in contemporary society, the impact of social media platforms in everyday life and how libraries can use social media tools to achieve their goals. Thus, libraries in the West have better understood that promoting online activity is one of the most effective ways to attract users, an example that should be followed by libraries in Romania, whereas the progress made by them through social networks is evidenced by the statistics attesting to the increase in the number of users. Developments in technology and the presence of the Internet in the Romanian libraries are an advantage these institutions should use more to achieve their goals and objectives being a fast and efficient means of communication. [ABSTRACT FROM AUTHOR]