During the last years, bioethical discussion has highlighted the role of the patients’ autonomy, being informed consent its particular expression, about decisions that they should make about their own health. The Hippocratic tradition, the deontological positions of the Geneva Declaration of the World Medical Association and numerous codes of ethics in various countries, require that the physician, above all, should ensure patients’ health. In this context the discussion on pros and cons for the so-called “therapeutic privilege” are discussed. The “therapeutic privilege” refers to the withholding of information by the clinician during the consent process in the belief that disclosure of this information would lead to harm or suffering of the patient. The circumstances and conditions in which this privilege can become valid are discussed. Special reference is made in order to respect multiculturalism and to the possibility of obtaining advice from health care ethics committees. The role of prudence in the doctor-patient relation must be highlighted. Disclosure of information should be subordinated and oriented to the integral well-being of the patient.