It is often maintained that, since the buying and selling of organs—particularly the kidneys—of living people supposedly constitutes exploitation of the living vendors while the so-called “altruistic” donation of them does not, the former, unlike the latter, should be a crime. This paper challenges and rejects this view. A novel account of exploitation, influenced by but different from those of Zwolinski and Wertheimer and of Wilkinson, is developed. Exploitation is seen as a sort of injustice. A distinction is made between (...) justice and fairness. To exploit someone is to take advantage of him or her unjustly. Exploitation pertains to the nature of actions, interactions, and transaction rather than to their outcomes or to how they are perceived by exploitees. Desperation on the part of one or other of the parties to a transaction does not preclude the giving of valid consent to the transaction. Disparities of power or wealth between the parties to a transaction do not indicate or entail that the transaction will be exploitative. A disparity in the benefits that arise from a transaction between the parties does not indicate or entail that exploitation has taken place. (shrink)