Businesses interact with different stakeholders and stakeholders groups in the environment in which they work. Each of these stakeholder groups has a number of expectations from businesses. In this context, it can be seen that corporate social responsibility activities contribute positively to the common expectations and satisfaction levels of the stakeholders. Corporate social responsibility strategies and practices of businesses have the potential to provide competitive advantage. Borsa Istanbul (BIST) Sustainability Index measures the level of giving importance to sustainable policies for the solution of social and environmental problems. From this point it is important that social responsibility activities of the organizations included in the BIST Sustainability Index. The purpose of this study conducting content analysis for corporate social responsibility activities of businesses in BIST Sustainability Index. Corporate social responsibility activities of companies with high level of corporate sustainability performance are considered as a guide. Therefore, the content of corporate social responsibility activities of companies and to see how the differences develop is important in terms of sectoral differences. In the result of the study, it was found that the CSR activities tendency of the companies in the Sustainability Index differed in terms of enterprise and sector groups.