BackgroundIn its 2015 decision in Montgomery v. Lanarkshire Health Board, the Supreme Court of the United Kingdom overruled the long-standing, paternalistic prudent doctor standard of care in favour of a new reasonable patient standard which obligates doctors to make their patients aware of all material risks of the recommended treatment and of any reasonable alternative treatment. This landmark judgment has been of interest to the rest of the common law world. A judicial trend of invoking Montgomery to impose more stringent (...) requirements on doctors is discernible in subsequent decisions since then.Main bodyIn this narrative review, without questioning the idea that properly informed patients should play a more active role in procedures affecting their own health in furtherance of their autonomy, safety, and consumer rights, we identify and analyse, with the aid of realistic clinical thought experiments, three practical conundrums that the Montgomery standard may inflict on the daily work of doctors, unfairly exposing them to arbitrary legal risks.ConclusionsThese conundrums pertain to the ascertainment of the risks that must be disclosed to the patient under the test of ‘materiality’; the legal uncertainty as to the scope of the exceptions; and the actual ability of doctors to cope with the pressures of time. These conundrums offer ripe opportunities to rethink the proper role of judicially developed medical law in modern health care practice. (shrink)