The topic of the paper is social media in the role of public relations tools on the example of cities and municipalities in county of Požeško-Slavonska. The paper presents the situation with social media of local governments in that county. At the very beginning, there is an overview of the most important information about municipalities and cities whose posts on social networks were analyzed. The paper presents and explains the concept of media, mass media and their historical development. The focus is on the functions of the media and their importance in the daily life of the individual and society. In one of the chapters was presented the origin and spread of the three studied social networks - Facebook, Instagram and YouTube. There are listed the most important facts about each of the mentioned networks are, as well as the advantages of their use. After that, in paper was explained the notion of public relations, presented a historical overview of their origin, and stated the modern technological advantages that benefit from public relations. The sixth chapter presents the results of the analysis of the quantity and type of publications on social media of cities and municipalities in county of Požeško-Slavonska, which is also the main part of the paper. In the same chapter, along with the results of the research, there are suggestions for better use of the potential of social media as a tool for public relations of the observed cities and municipalities. In addition to the research of publications, was conducted a survey among the inhabitants of the county, and the results are presented in the last chapter of the paper.