Although the sociology of medicine has developed a rich body of research on patients’ experiences and how they handle their illnesses, few analyses have examined doctors’ concepts of disease. Building on previous research findings that doctors consider some diseases to be more worthy than others, this article focuses on how these differences in disease prestige are articulated and made logical. We presented a focus group panel of doctors a table of 38 diseases rank-ordered by prestige according to the results of a previous quantitative study of doctors. We prompted a lively discussion among the doctors by asking them whether they were familiar with this rank order. In analysing how they managed the prestige knowledge presented to them, we focused on how they handled the value conflict between this informal rank order and the formal value of equality of treatment. Using positioning theory as a theoretical premise and a methodological tool, we found that the focus group participants created positions in their conversations that allowed them to present and discuss views on disease prestige that would be considered illegitimate if they were declared directly. However, they were able to do so without being forced to take a personal stand. Thus, we demonstrate how informal disease rankings can be produced and reproduced.