<p>This article discusses the most plausible moral basis for using severity as a priority setting criterion in healthcare: prioritarianism or egalitarianism. We argue that prioritarianism is superior, since egalitarianism has several problems that prioritarianism avoids. We have elaborated three such problems. First, egalitarianism arguably needs a non-equality-based reference level in order to determine the magnitude of severity. Second, it has the problem of irrelevant alternatives: the assessment of the severity of one person’s illness varies depending on the condition of other persons, even when their health status has not changed. Third, egalitarianism introduces excessive complexity, as it must explain what aspects of inequality matter, and why, in relation to illness severity. By contrast, prioritarianism has some benefits that egalitarianism lacks: it aligns theoretically with the concept of severity as a priority setting criterion in healthcare, and it explains why we always have a pro tanto reason to improve someone’s health without having to rely on other theories. In the end, if equality of health matters, it is arguably not because of its connection to severity.</p>