A socially responsible company is the one that, while taking care of its economic effects, also decides to voluntarily promote the well-being of the community through concern for the society and the environment. In 2006, the Croatian Chamber of Commerce and the Croatian Business Council launched a joint initiative to develop a methodology for evaluating corporate social responsibility practices, with the aim of increasing the understanding and importance of corporate social responsibility (CSR) in the Republic of Croatia. The methodology of the CSR Index includes different criteria for evaluating voluntary corporate socially responsible business practices. The CSR Index initiative has been implemented since 2007, and it honors those companies that have the best achievements in corporate social responsibility. In this way, other companies are encouraged to become involved and to raise public awareness of the importance of CSR. This paper defines and explains ethics and corporate social responsibility, shows the development of corporate social responsibility in the world and the Republic of Croatia, presents the institutions that promote corporate social responsibility, and three organizations that participated in the CSR index and received recognition in categories of large, medium and small businesses. Based on publicly available data, the corporate social responsibility practices of the selected companies are analysed and conclusions are defined. It can be seen that the corporate practices of the selected companies are different and are custom to the size and type of the company. Also, it can be concluded that the selected companies, based on their concern and commitment to the environment and society, were justified to receive the awards of the CSR Index initiative.