There are three types of solutions to the problems deriving from companies' ethical, social and environmental responsibilities: those based on regulation by an authority or agency; those deigned to create market incentives; and those that rely on self-regulation by companies themselves. In the specific field we are concerned with here, regulation has significant costs and drawbacks that make it particularly desirable that companies should set up their own ethical, social and environmental management systems or programmes. The purpose of this article (...) is twofold. On the one hand, it explains how implementing voluntary ethical, social and environmental management systems or programmes may help to develop and sustain ethical behaviour in organizations, overcoming the conflict between compulsory regulation and occasional ethical practices. On the other hand, it shows that conditions must be met for an ethical management programme to be effective. (shrink)