Socially responsible business is increasingly used as a term by companies in their business on the market to give a better impression to the social community, investors, employees, customers and all the participants in the market they work with. This thesis describes the basic concepts of sustainable development, the importance of socially responsible business and the strategy of competitive advantage. The greatest emphasis was put on the impact of the sustainable development of the chosen company (dm-drogerie markt d.o.o. Zagreb) on business and its competitive advantage. For several years in a row they have been chosen for „Employer of the year“, proving to be the leaders on the labour market. High salaries and the concern for society and environment are just some of the facts which make this company so special. At dm, person is always a key business factor, either as a customer or as employee. It also describes the changes that sustainable development brings to business operations and how sustainable development activities can contribute to the competitiveness of a selected company. A survey was conducted in the area of Zagreb, where 207 respondents participated and the results of two methods of data collection - surveys and interviews and content analysis were analyzed. In the first part of the research, the aim was to establish customer attitude and awareness towards sustainable development while the second part of the research related to the selected company or how many buyers noticed the campaigns and social initiatives that the selected company carried out.