In this paper, we examine the lawfulness of a proposal to provide elective ventilation to incompetent patients who are potential organ donors. Under the current legal framework, this depends on whether the best interests test could be satisfied. It might be argued that, because the Mental Capacity Act 2005 (UK) (and the common law) makes it clear that the best interests test is not confined to the patient's clinical interests, but extends to include the individual's own values, wishes and beliefs, (...) the proposal will be in the patient's best interests. We reject this claim. We argue that, as things currently stand, the proposal could not lawfully be justified as a blanket proposition by reference to the best interests test. Accordingly, a modification of the law would be necessary to render the proposal lawful. We conclude with a suggestion about how that could be achieved. (shrink)