Reducing diagnostic error is an area of increasing focus within patient safety. However, little is known about how patients perceive physician communication regarding diagnostic uncertainty. In this study, participants (parents of pediatric patients) were assigned to read one of three clinical vignettes each describing a different approach to a physician communicating diagnostic uncertainty; they were then asked to answer a questionnaire. Researchers found that explicit expression of diagnostic uncertainty by a physician was associated with negative perceptions of physician competence as well as diminished trust and satisfaction with care, whereas more implicit language was not. A past Annual Perspective highlighted some of the challenges associated with diagnostic error.