Advancements in different field of medicine have given rise to complex ethical dilemmas in clinical practice. The more the clinicians are sensitized to ethical problems and familiar with ethical decision-making, the more they can value professionalism in their practice. The current paper is designed to emphasize physicians to think ethically in the field of internal medicine and endocrinology. Being aware of the ethical issues and being sensi-tive to them are the first steps for ethical conduct. So, some important ethical issues will be described in brief, and an overview of professionalism and the principles of ethical decision making will be provided. Three ethical cases are included in order to make the discussion more practical.