As a result of numerous, highly publicized, ethical breaches, firms and their agents are under ongoing scrutiny. In an attempt to improve both their image and their ethical performance, some firms have adopted ethical codes of conduct. Past research investigating the effects of ethical codes of conduct on behavior and ethical attitudes has yielded mixed results. In this study, we again take up the question of the effect of ethical codes on ethical attitudes and find strong evidence to suggest that (...) business professionals employed at firms with ethical codes of conduct are significantly less accepting of ethically questionable behavior toward most stakeholders. One notable exception relates to ethical actions toward customers. (shrink)