BackgroundImpostor phenomenon, also referred to as imposter syndrome or impostorism, was initially identified among high achieving women who felt undeserving of their successes because they felt they were earned through luck or chance, rather than skill or experience. It’s prevalence has been identified in many health professions; however, there are no known studies of Registered Dietitians’ (RDs) perceptions of impostor phenomenon. This study assesses the following among RDs: [1] prevalence of impostor phenomenon and differences in impostor phenomenon levels, if any, based on [2] highest educational level achieved and [3] years of experience as an RD.MethodsA cross-sectional survey was sent electronically to 5,000 RDs credentialed by the Commission on Dietetic Registration in the United States. Respondents’ agreement with 20 impostor phenomenon statements from the Clance Impostor Phenomenon Scale were measured. The sum score from the scale was used to classify levels of impostor phenomenon. Descriptive statistics and chi square analyses for comparison were evaluated.ResultsOf the 445 (9%) who began the survey, 266 (5%) completed it and were included in analyses. Over 76% of 266 individuals reported at least moderate impostorism (score of 40 or fewer points out of 100). No difference was seen based on educational level (p= .898); however, those with less than five years’ experience reported higher impostor phenomenon (p< .05). Among those with five to 39 years’ experience, over 40% reported moderate impostorism.ConclusionImpostor phenomenon is prevalent among RDs. Moderate impostorism was pervasive among all those with less than 40 years’ experience and could potentially negatively impact these respondents. Future research could explore ways to reduce impostor phenomenon in RDs.