In the first part, this article identifies the main solutions proposed by contemporary theories of justice for the distribution of scarce goods. In the second part of the paper, it applies them to the ideal models of public health systems. In other words, the paper investigates criteria of distributive justice in the provision of health services (treatments or medications), by means of benefits, by the State, to any individual, regardless of their financial condition or the cause of the illness (involuntary or provoked). These two elements of delimitation are not absolutely morally neutral, but for didactic purposes, they are isolated and disregarded in the discussion that is proposed. The conclusion is that, behind fundamental choices regarding the limits and distribution of health services, a criterion of justice is perfectly identifiable and sometimes irreconcilable with other options. The problem of this paper consists in the delimitation of what is fair in the provision of treatments from the point of view of different conceptions of justice. The methodology used is descriptive of the current state of the discussion about theories of justice, followed by a dialectical application to the examination of ideal models of health systems.