The paper reviews the theoretical basis for the application of user fees in the public health sector in low-income countries with particular reference to the special characteristics of medical care as a commodity. The general equilibrium efficiency result of the market mechanism is shown to be the theoretical justification for the financing of health services via a system of user charges. If markets for all goods and services exist, and are perfect in a very strict sense, the welfare outcome of the price mechanism cannot be improved upon by any other resource allocation device. Furthermore, the decentralized and impersonal nature of this mechanism renders it more convenient to use in the allocation of commodities, health care included, than its alternatives such as a system of centrally administered prices or a system of administrative controls and directives. However, since many of the assumptions of the price system are rarely met in actual situations, especially in the health sector, it should be applied with caution. In particular, problems of information asymmetry and consumption externalities in health care markets necessitate a simultaneous use of fees with government interventions in order for fees to achieve their often intended aim of efficiency and equity improvement in health care provision. The most important intervention of the government here is the enactment and enforcement of institutions that reduce costs of transacting in health care markets and that in addition facilitate the emergence of new markets such as the markets for medical insurance. A striking finding of the paper is that health services in low-income countries are best financed primarily by revenue from general taxation, supplemented by a system of moderate user fees. Since medical insurance markets are generally non-existent in low-income areas, it is argued that financing health services primarily through user fees in such areas would be inefficient and inequitable. However, to mitigate the moral hazard problem as well as the problem of the commons, both of which characterize publicly financed health care, imposition of modest user fees is required. The importance of fees in this proposal increases with economic growth and with evolution of institutions that facilitate market transactions. Strategic interaction among economic agents is shown to affect the structure and implementation of user fees. A game-theoretic analysis of the general problem of health care financing shows that this problem is best tackled by harnessing the efforts of households, private health care providers, the government and civil society. These entities form what might be called a winning coalition in health care financing game of society. It is argued that the government is better placed to provide an institutional framework for coordinating the efforts of the various players to the desired end.