The diploma thesis deals with the use of marketing strategies as tools of civil sector organizations to promote public interests. The first part of the thesis serves to clarify the theory of organized civil sector, marketing strategies of civil sector organizations and the legislative process in the Czech Republic, including clarification of the concept of public interest. The second part of the thesis consists of qualitative empirical research, which aims to describe the whole form of the selected campaign created to promote public interest in the form of legislative change while understanding how campaigners evaluate the campaign and how they perceive cooperation between civil society organizations and marketing agencies for the implementation of the campaign. The chosen research method is a case study of the successful marketing campaign of the czech civic sector organization Svoboda zvířat, which contributed to the promotion of the public interest. By using data analysis and semi-structured interviews the case study acquaints the reader with the key circumstances of the selected campaign, its proposed marketing strategy including its explanation, with the campaign implementation process including the context of the legislative process of the public interest, with evaluation of the campaign from...