Over the long-term, companies, their managements and even employees have been facing increasing external demands from customers, business partners, as well as wider society, to behave ethically. At the same time, similar demands and requirements have been coming from within companies themselves in relation to performance management and employee motivation. These demands are plac ing greater emphasis on the need for ethical management and a code of ethics as the primary tool for promoting and enforcing the ethical conduct of an organisation, its management and employees. This paper focuses on the prevalence and role of codes of ethics in Czech companies, their goals and contents, the principles behind their creation and enforcement, as well as the main prerequisites for their efficacy. It is based on an extensive longitudinal analysis of a broad sample of 1,242 Czech companies of various sizes, the main aim of which was to determine the aforementioned and, in addition, whether those companies that have created codes of ethics, strengthen the consistency of their use by regularly evaluating and updating their contents.