In the United Kingdom, the debate about how best to meet the shortfall of organs for transplantation has persisted on and off for many years. It is often presumed that the answer is simply to alter the law to a system of presumed consent. Acting perhaps on that presumption in his annual report launched in July, the Chief Medical Officer, Sir Liam Donaldson, advocated a system of organ donation based on presumed consent, the so-called “opt-out” system.1 He is calling for (...) a change in the law in England and Wales whereby consent to organ donation is presumed, making a person’s organs automatically available for transplantation after death, unless they registered objections to this while alive. Subsequently, the British Medical Association lent its support to the introduction of such a system.2 The BMA contends that “the practice of presumed consent legislation has had a significant effect on the number of cadaveric donors per million population.”2It is often taken for granted that there must be a correlation between the enactment of legislation on presumed consent and an increase in organ donation and procurement. However, the correlation is not as straightforward as it might seem. It may be that other practical measures to encourage organ donation could be implemented without changing the Human Tissue Act 2004, an Act which has been in force for barely a year.An analysis by Abadie and Gay demonstrated that “presumed consent legislation has a positive and sizeable effect on organ donation rates”,3 but they themselves admitted that the correlation between rates of donation and presumed consent legislation is “not completely unequivocal”.3 It is true that among the most successful cases in procurement rates are countries with presumed consent legislation . However, since some of the …. (shrink)