A growing number of professional associations and occupational groups are creating codes of ethics with the goal of guiding their members, protecting service users, and safeguarding the reputation of the profession. There is a great deal of literature dealing with the question to what extent ethical codes can achieve their desired objectives. The present paper does not contribute to this debate. Its aim is rather to investigate how rational it is to comply with codes of conduct. It is natural and (...) virtually inevitable for a reflective person to ask why one should pay any attention to ethical codes, in particular if following a code is not in one’s own interest. In order to achieve the aim of this paper, I shall (in “Quasi-reasons for complying with an ethical code” section) discuss reasons that only appear to be reasons for complying with a code. In “Code-independent reasons” section, I shall present genuine practical reasons that, however, turn out to be reasons of the wrong kind. In “Code-dependent reasons” section finally presents the most important reasons for complying with ethical codes. The paper argues that while ethical codes do not necessarily yield reasons for action, professionals can have genuine reasons for complying with a code, which may, however, be rather weak and easily overridden by reasons for deviating from the code. (shrink)