BackgroundUncertainty is ubiquitous in medical practice. The Pediatrics Milestones from the Accreditation Council on Graduate Medical Education state that advanced learners should acknowledge and communicate about clinical uncertainty. If uncertainty is not acknowledged, patient care may suffer. There are no described curricula specifically aimed to improve learners’ ability to acknowledge and discuss clinical uncertainty. We describe an educational intervention designed to fill this gap.MethodsSecond-year pediatric residents engaged in a two-phase simulation-based educational intervention designed to improve their ability to communicate about diagnostic uncertainty with patients and caregivers. In each phase, residents engaged in two simulated cases and debriefs. Performance was assessed after each simulated patient encounter using standardized metrics, along with learner perceptions of the experience.ResultsResidents’ skills in communicating with patients and families about diagnostic uncertainty improved after this intervention (mean score post 3.84 vs. 3.28 pre on a five-point Likert scale, pConclusionsThis prospective study suggests that a simulation-based intervention was effective in improving resident physicians’ skills in communicating about diagnostic uncertainty with patients and families. Further study is needed to determine how learners perform in real clinical environments.