The purpose of this paper is to analyse the importance of ethics in today's business. The concept of business ethics, which has been debated since the beginnings of trade, seems to be an oxymoron and the attention this controversial topic drew increased strongly in the last years. The changing relationships between the legislative role of governments and the regulations by businesses emphasize the important role of enterprises in the global economy. In this paper, the change in business ethics and their main impacts will be discussed as well as the influence of codes of ethics as an instrument of business ethics.