Informed consent is required for any medical procedure although the situations in which it is given are beset by uncertainties and indeterminacies. These make medicolegal scrutiny of such situations very difficult. Although some people find the decision in the Sidaway case incomprehensible because of its continuing regard for a 'professional practice standard' in informed consent, I will argue that an important fact in many cases is the moral integrity of the doctor concerned and the pattern of his practice. This may (...) provide the only morally principled and legally accessible evidence enabling a correct decision to be made in a difficult case. Although the epistemological significance of a professional practice standard is thereby defended the 'prudent patient standard' for what counts as consent is left intact. (shrink)