Professional control in the selection of treatment options for patients is changing. In light of social and legal developments emphasising patient choice and autonomy, and restricting medical paternalism and judicial deference, this article examines how far patients and families can demand NHS treatment in England and Wales. It considers situations where the patient is an adult with capacity, an adult lacking capacity and a child. In all three cases, there is judicial support for professional autonomy, but there are also inconsistencies (...) that have potential to elevate the importance of patient and family preferences. In combination, they may be perceived by healthcare professionals as an obligation to follow patient preferences, even where doing so conflicts with other professional obligations. It is argued that a more nuanced approach to shared decision-making could help clarify the boundaries of decision-making responsibility. (shrink)