This paper challenges the leading common morality accounts of medical ethics which hold that medical ethics is nothing but the ethics of everyday life applied to today’s high-tech medicine. Using illustrative examples, the paper shows that neither the Beauchamp and Childress four-principle account of medical ethics nor the Gert et al 10-rule version is an adequate and appropriate guide for physicians’ actions. By demonstrating that medical ethics is distinctly different from the ethics of everyday life and cannot be derived from it, the paper argues that medical professionals need a touchstone other than common morality for guiding their professional decisions. That conclusion implies that a new theory of medical ethics is needed to replace common morality as the standard for understanding how medical professionals should behave and what medical professionalism entails. En route to making this argument, the paper addresses fundamental issues that require clarification: what is a profession? how is a profession different from a role? how is medical ethics related to medical professionalism? The paper concludes with a preliminary sketch for a theory of medical ethics.