The core of corporate governance is composed of values such as transparency, accountability, fairness and responsibility. The principles of corporate governance and ethical approach are built on these core values. Consequently, there is a need for guidelines on how managers and other employees should behave ethically on certain issues. In this context, the aim of the study is to identify the concepts emphasized in the ethical declarations of companies and to reveal the focus themes, differences and similarities of the sectors and companies included in the Corporate Governance Index in Turkey. Content analysis method, one of the qualitative research methods, was performed in the study. The reason for the selection of companies included in the BIST Corporate Governance Index as a sample is because of the fact that the companies within this index have certain standards in terms of corporate governance and ethical principles and they are accepted as cynosure for other companies. As a result of this research, the themes that the company and sector groups intensified were determined and significant differences have been identified among companies and sectors.