The paper provides an insight into the concepts of defining public relations. Public relations, an instrument for every company to reach the desired group of consumers and help them to strengthen their own reputation, public image. Due to the important impact on the business of every company, public relations cannot and must not be ignored. An overview of them throughout history, their development and growth driven by the development of technology and the use of the Internet. The theoretical part seeks to define the framework of the approach to measuring the business performance of organizations through qualitative and quantitative measurement models. Public relations with its impact on interest - influential groups are analyzed through its impact on business performance and the importance they give to the image of companies. Following the theoretical determinants of the model that measure the impact of this relationship, examples of three companies are given to see the importance of good public relations on business, stock market prices, dividends, financial indicators and the impact of these companies on cooperation with society and society. The companies observed in this thesis are Valamar Riviera d.d., Hrvatski Telekom d.d. and Krašd.d. All three companies are listed on the Zagreb Stock Exchange and are among the most successful companies in Croatia.