Fundamental to a proper doctor–patient relationship is the assurance that information provided by the patient to the treating doctor will remain strictly confidential. Doctors must be free to ask their patients any questions necessary for diagnosis and treatment, and patients must be willing to trust doctors by giving full answers. Maintaining such trust has a wider social benefit of ensuring that medical practice serves to promote and maintain the health of the community. The basis of this trust lies in one of the oldest ethical principles of medical practice stated in the Hippocratic Oath as:

This same obligation has since been repeated in the World Medical Association Declaration of Geneva as ‘I will respect the secrets confided in me, even after the patient has died’.

This ethical requirement for confidentiality, well understood by doctors, has been overlaid in Australia in recent years by the progressive introduction of privacy legislation at the federal level and in some states, which for doctors covers very much the same territory as this ethical requirement. As a result, doctors now need to understand the ethical and legal bases of their professional obligations in this regard. In this chapter, both bases are described and explained.