Overtesting, the downstream consequences of overdiagnosis, and overtreatment of some patients are topics of growing debate within emergency medicine (EM). The "Preventing Overdiagnosis" conference, hosted by The Dartmouth Institute for Health Policy and Clinical Practice, with sponsorship from consumer organizations, medical journals, and academic institutions, is evidence of an expanding interest in this topic. However, EM represents a compellingly unique environment, with increased decision density tied to high stakes for patients and providers with missed or delayed diagnoses in a professional atmosphere that does not tolerate mistakes. This article reviews the relevance of this reductionist paradigm to EM, provides a first-hand synopsis of the first "Preventing Overdiagnosis" conference, and assesses barriers to moving the concept of less test ordering to reality.