In modern business, the market is saturated and cries out for innovation, so companies have an increasingly demanding role to find a way to, in addition to the basic goal of producing a product, provide customers with added value that will keep them. Companies that want to survive in the market and stand out from the environment should choose a strategy that brings a sustainable competitive advantage. In this paper, the focus is on the differentiation strategy presented on the example of Brodene Hartmann, which has pronounced advantages with which it achieves increasing success in the market. In addition to analyzing the competitive advantages of companies, the concept of sustainable business is described, which is closely related to contemporary environmental global issues. The paper is divided into three parts. In the first part, the strategy of differentiation as well as the determinants of competitiveness are presented through a theoretical framework. The observed industry, the main leading entities and the environmental components of sustainable business were also presented. The second part describes the history of Hartmann and analyzes the sources of competitive advantage that the company has in the market. An analysis of the company was made through the most important strategic tools and the company's capabilities were interpreted, as well as weaknesses and shortcomings. The gap between the theoretical and the actual case is described and guidelines are given for achieving a long-term sustainable competitive advantage. The third part of the paper provides an overview of the case analysis, implications and recommendations related to the differentiation strategy that the company applies. The contribution of the work is manifested in the analysis of the internal profile of the company through highlighting potential advantages and disadvantages, assessing the competitiveness and attractiveness of the packaging industry and presenting a differentiation strategy related to environmentally friendly solutions with emphasis on sustainable development.