The aim of this study is to determine the weighting of the PR application areas used in the reports prepared by companies on their corporate sustainability activities and to identify the differences and similarities in the PR application areas on a sectoral basis. To this end, the study carried out a thematic analysis of the public relations practices in the corporate sustainability reports, annual reports and integrated annual reports of the companies included in the BIST 30 Index in 2021 on a sectoral basis. The study focuses on the public relations practices used in the reports prepared as a result of the sustainability activities carried out by companies in an institutional manner within the framework of the Sustainable Development Goals. In this context, it is known that there is variation in the PR practices used in the reports produced as a result of corporate sustainability activities. The dimensions of this variation have been studied using the method of content analysis. In the light of all these data, the extent to which public relations practices are included in the reports produced within the framework of corporate sustainability activities and, in this context, the importance of the discipline of public relations in corporate sustainability activity reports has been revealed. As a result, using the content analysis method, it was found that the companies included in the 2021 BIST 30 Index included the content of corporate social responsibility activities in the first place among the public relations application areas in their sustainability reports. After corporate social responsibility activities, it was observed that employee member relations came second and marketing communication came third.