Rationale, aims, and objectives This paper examines a remarkable dispute between Dutch insurers, hospitals, doctors, and patients about a set of quality indicators. In 2013, private insurers planned to drastically reform Dutch emergency care using quality indicators they had formulated drawing from clinical guidelines, RCTs, and systematic reviews. Insurers' plans caused much debate in the field of emergency care. As quality indicators have come to play a more central role in health care governance, the questions what constitutes good evidence for them, how they ought to be used, and who controls them have become politically and morally charged. This paper is a case study of how a Dutch public knowledge institution, the National Health Care Institute, intervened in this dispute and how they addressed these questions. Method We conducted ethnographic research into the knowledge work of the National Health Care Institute. Research entailed document analysis, participant observation, in-depth conversations, and formal interviews with 5 key-informants. Results The National Health Care Institute problematized not only the evidence supporting insurers' indicators, but also-and especially-the scope, purpose, and use of the indicators. Our analysis shows the institute's struggle to reconcile the technical rationality of quality indicators with their social and political implications in practice. The institute deconstructed quality indicators as national standards and, instead, promoted the use of indicators in dialogue with stakeholders and their local and contextual knowledge. Conclusions Even if quality indicators are based on scientific evidence, they are not axiomatically good or useful. Both proponents and critics of Evidence-based Medicine always feared uncritical use of evidence by third parties. For non-medical parties who have no access to primary care processes, the type of standardized knowledge professed by Evidence-based Medicine provides the easiest way to gain insights into "what works" in clinical ...