Improvements in surgical procedures and immunosuppressive practices have greatly increased the range and success rate of organ transplants. Unfortunately, supply does not meet demand, and demand is increasing. This paper documents the current level of unsatisfied demand for several transplantable organs, and argues that the extant system of altruistic organ donation is unlikely ever to provide adequate supply because of lack of incentives to donate and the ambiguity surrounding property rights over transplantable organs. A greater reliance on markets would help attenuate these problems. However, unorganized private spot markets for human organs are likely to be both inefficient and inequitable, and are perceived as morally offensive. A feasible alternative is an organized. publicly operated future delivery market, wherein an individual can contract, for valuable consideration, with a government agency for delivery of a specific organ upon death. The implementation of such a market would encounter difficult (but not intractable) problems such as price determination, the selection of a medium of exchange, and contractual issues, particularly the role of minors in such a system. Finally, it is argued that such a market is superior to the much-discussed compulsory expropriation alternative.