Corporate social responsibility is becoming important component of business strategy that strives to meet increasingly demanding ethical, environmental, legal, commercial and public standards. There are four areas of application of corporate social responsibility: the marketplace, the workplace, the community and the ecological environment. This paper seeks to present significant influence of society’ on contemporary business in the Republic of Croatia as well as the importance of applying corporate social responsibility as an effective tool for gaining competitive advantage. The application of corporate social responsibility is slower in Croatia and some of the reasons are: poorly managed transition, war that marked the end of the 20th century, economic crisis in year 2008 and lack of government incentives. Despite these problems, the situation in Croatia has improved over the years and more small-sized and large enterprises apply corporate social responsibility. In the practical part of this paper, application of corporate social responsibility in small-sized and large enterprise will be presented. Selected enterprises are part of a growing association in the City of Osijek called "Osijek Software City". This way, the same environment (City of Osijek) and the same sector of business activities (IT technology) have been taken into account. Inchoo d.o.o. has been selected as an example of a small-sized enterprise which has 45 employees, and Span d.o.o. has been selected as an example of a large enterprise with more than 300 employees.