Corporate social responsibility has become a very important component of a company's performance. Companies operate in a social and ecological environment and are expected to follow the rules and norms of the environment in which they are located, in addition to the laws set by the authorities. The purpose and aim of this paper are to define corporate social responsibility, its characteristics and purpose of application, to give an overview of its development in the world and in Croatia, and to show the successful implementation of corporate social responsibility on the example of small and medium enterprises. The dimensions through which corporate social responsibility is realized within the economy are economic, legal, moral, and philanthropic. The concept of corporate social responsibility is associated with the topic of sustainable development and a triple bottom line approach that combines economic security, social justice, and ecological balance as three pillars of sustainable development. The development of corporate social responsibility as it is known today began in the 1950s and was first mentioned by Howard Bowen. The concept of business ethics is also frequently associated with the concept of social responsibility and is a key factor in achieving the moral dimension of corporate social responsibility as well as its successful implementation in a company. Business ethics is achieved through four levels and is described through three fundamental principles: beneficence, fairness and justice. The empirical part of the paper refers to the implementation of corporate social responsibility on the example of Media Val d.o.o. as a small company and HiPP Croatia d.o.o. as a medium company. Media Val is a communication management and consulting company. The HiPP company manufactures food products for children and pregnant women.