Marketing has a significant role in modern business and its importance is recognized both in the private and the public sector. It is important to distinguish the function of marketing from sales function. The marketing concept ensures the satisfaction of consumer needs by exploring these needs and desires and creating products. There is an increase in profits by creating products that are in demand on the market. As in private, marketing is also important in the public sector as the company strives to get closer to consumers and meet their needs. The public sector, among other things, is made up of public companies, which are state-owned or controlled, and their performance contributes to the economy. Public companies therefore use marketing to attract new and keep and inform existing consumers. Given that the subject of this paper is marketing in the public sector, as an example of the application of the same was chosen Adriatic Croatia International Club d.d., the company that belongs to public sector. In the first part of the paper, along with the methodology of work, marketing, its meaning and development are defined. In addition, the importance of social marketing has been emphasized and these are the parts of the marketing sphere. Furthermore, the concept of public sector is defined, its features are highlighted and the structure of the public sector in the Republic of Croatia is explained. The role that marketing has in improving the public sector's business is defined below, and the mechanisms that contribute to it, as well as partnerships between the various sectors, are defined. Application of marketing in one public company is presented on the example of ACI d.d. at the end of the work.