Leaving a better livable world for future generations is a duty of businesses as well as every individual. This task is a requirement of social responsibility. Nowadays, as businesses focus on maximum profits, they may be in conflict with their social responsibilities. The aim should not only be to achieve maximum profit, but also to contribute to the sustainability of the environment. When we look at the financial statements of the enterprises, a cost element for the environment is very rare. The implementation of the environmental accounting system will fill this gap. And thus, the investment costs of the enterprises to the environment will be included in their financial statements. In developed countries, for instance Japan and Sweden, environmental costs are clearly seen in the financial statements. In this study, were examined sustainability, social responsibility and environmental activities of 63 businesses in the BIST Sustainability Index. In addition, it is examined whether companies show environmental costs in their financial statements and whether they apply environmental accounting. As a result of the study, it was determined that enterprises do not apply environmental accounting, and general information rather than numerical information about environment is included in financial reports and sustainability reports.