The relationship between Corporate Social Responsibility (CSR) and environmental costs has started to play an important role in the sustainability strategies of businesses in recent years. CSR encourages businesses to fulfill their environmental and social responsibilities by going beyond the sole purpose of profit. Practices by companies to minimize their environmental impacts both increase their financial performance and strengthen their reputation in the eyes of society in the long term. Environmental costs refer to the expenses made by businesses to eliminate the damage they cause to the environment as a result of their activities and to ensure sustainability. These costs directly and indirectly require businesses to develop environmentally sensitive processes. Correct calculation and management of environmental costs play a critical role in businesses achieving their environmental sustainability goals. Practices such as waste management, carbon emission reduction and water recovery within the scope of CSR projects both reduce environmental costs and increase the competitive advantage of companies. For example, projects aimed at reducing carbon emission provide cost savings by allowing businesses to avoid environmental taxes. In addition, reporting environmental costs and making these costs visible on financial statements helps companies develop better environmental management strategies. The relationship between CSR and environmental costs has positive effects not only on the environmental sustainability of businesses but also on their financial performance. Environmental responsibility projects help businesses reduce their environmental damage, while achieving cost savings in the long term and strengthening their sustainability. In this context, calculating environmental costs and analyzing the effects of CSR projects have become an important tool for businesses to achieve their sustainable development goals. In particular, the adoption of innovative environmentally friendly practices not only increases the reputation of businesses but also improves their operational efficiency, providing long-term competitive advantage.