There is a common view in medical ethics that the patient's right to be informed entails, as well, a correlative right not to be informed, i.e., to waive one's right to information. This paper argues, from a consideration of the concept of autonomy as the foundation for rights, that there can be no such ‘right’ to refuse relevant information, and that the claims for such a right are inconsistent with both deontological and utilitarian ethics. Further, the right to be informed is shown to be a mandatory right (though not a welfare right); persons are thus seen to have both a right and a duty to be informed. Finally, the consequences of this view are addressed: since the way in which we conceptualize our problems tends to determine the actions we take to resolve them, it is important properly to conceptualize patients' requests not to be informed. There may be many reasons for acting in accord with such a request, but it is a mistake to conceptualize one's act as ‘respecting a right possessed by persons’.