BACKGROUNDImposter Syndrome (IS), or Imposter Phenomenon (IP), is marked by persistent self-doubt and fear of being exposed as a fraud despite success. It's prevalent in high-achieving fields like medicine and is linked to anxiety and perfectionism. The Clance Imposter Phenomenon Scale (CIPS) is the most common assessment tool. This study aims to translate and validate an Arabic version of CIPS for Arabic-speaking populations.METHODSThis cross-sectional study was conducted at King Saud University, Riyadh, from August to September 2024, using a convenient sampling method. The survey gathered demographic details and included the Arabic version of the CIPS, the General Self-Esteem Scale (GSES), and The Big Three Perfectionism Scale (BTPS). Data were analyzed using IBM SPSS 22 (p < 0.05). Construct validity was assessed through Exploratory and Confirmatory Factor Analysis. Internal consistency (Cronbach's alpha ≥0.7), test-retest reliability (ICC >0.75), and discriminant validity were evaluated. Concurrent validity was examined using structural equation modelling and Pearson's correlation with GSES and BTPS.RESULTSA total of 477 participants (66.5 % female, mean age 21.1 ± 2.0 years) completed the questionnaire. The Arabic CIPS demonstrated a three-factor structure in exploratory factor analysis (KMO = 0.936, Bartlett's test p < 0.001), with confirmatory factor analysis supporting good model fit (CFI = 0.87, RMSEA = 0.07). Internal consistency was excellent (Cronbach's α = 0.90), and test-retest reliability was acceptable (ICC = 0.71). Discriminant validity was supported by significant score differences across quartiles. CIPS correlated negatively with general self-efficacy (r = -0.39, p = 0.001) and positively with self-critical perfectionism (r = 0.68, p = 0.001) and rigid perfectionism (r = 0.46, p = 0.001), confirming its construct validity.CONCLUSIONThe Arabic CIPS is valid and reliable for use among medical and non-medical populations.