The international disparities in health and health-care provision comprise the gravest problem of medical ethics. The implications are explored of three theories of justice: an expanded version of Rawlsian contractarianism, Nozick's historical account, and a consequentialism which prioritizes the satisfaction of basic needs. The second too little satisfies medical needs to be cogent. The third is found to incorporate the strengths of the others, and to uphold fair rules and practices. Like the first, it also involves obligations transcending those to an agent's relations and fellow-citizens. These conclusions are applied to international health-care provision, which they would transform.