The concept of sustainable development is of growing interest to entrepreneurs, who wish to build a competitive advantage in the market by conducting their business in a sustainable manner. Sustainability reporting is related to the disclosure of information by entrepreneurs on the fulfilment of social, environmental and corporate governance (ESG) obligations in their business activities, complementing the traditional accounting principles concerning the financial situation of an entity, and under the adopted legal regulations it is becoming mandatory for larger companies and voluntary for others. It is a source of information for stakeholders as to the social and environmental impact of a company’s activities. This makes sustainability reporting and performance an extremely important part of building a company’s image –which also requires ensuring the reliability and transparency of the data disclosed. This article is devoted to sustainability reporting and includes an explanation of its essence, an overview of the legal regulations in force in the EU and in Poland, and an analysis of the opportunities and challenges for businesses obliged to report. The aim is to present the legal sources of sustainability reporting and the directions of its further development – taking into account the practical consequences for entrepreneurs – using a formal-dogmatic method and critical analysis.