People often choose the option that is better on the most subjectively prominentattribute — the prominence effect. We studied the effect of prominence inhealth care priority setting and hypothesized that values related to healthwould trump values related to costs in treatment choices, even when individualsthemselves evaluated different treatment options as equally good. We conductedpre-registered experiments with a diverse Swedish sample and a sample ofinternational experts on priority setting in health care (n = 1348).Participants, acting in the role of policy makers, revealed their valuation fordifferent medical treatments in hypothetical scenarios. Participants weresystematically inconsistent between preferences expressed through evaluation ina matching task and preferences expressed through choice. In line with ourhypothesis, a large proportion of participants (General population: 92%, Experts84% of all choices) chose treatment options that were better on the healthdimension (lower health risk) despite having previously expressed indifferencebetween those options and others that were better on the cost dimension. Thus,we find strong evidence of a prominence effect in health-care priority setting.Our findings provide a psychological explanation for why opportunity costs(i.e., the value of choices not exercised) are neglected in health care prioritysetting.