The article examines the scope of the legal duty of medical confidentiality when clinicians communicate information to the patient’s relatives. The subject is analysed in light of relevant developments in English law over the last decade, and in view of the growing shift in bioethics from individual to relational autonomy. The legal position and influential professional guidelines are then examined in light of accounts provided by NHS clinicians collected through in-depth interviews during 2009–2010. The clinicians experienced difficulties when facing tension between confidentiality and disclosure to relatives. They were dissatisfied with their restrictions in promoting an open channel of communication between patients and relatives, which they deem important and beneficial when patients face a serious illness. These findings lead the author to suggest several changes with regard to the doctor’s duty of confidentiality.