Literature shows that intolerance of uncertainty can have negative effects on the diagnosticprocess of health professionals. However, there is no intolerance of uncertaintymeasurement tools in French, so this study aimed at validating the Intolerance ofUncertainty Scale-12 (IUS-12) in French, and a version of the IUS-12 adapted for healthcareprofessionals (IUS-12-H).Methods:Five hundred and sixteen health professionals completed a French version of the IUS-12and the IUS-12-H, as well as several scales covering related constructs (e.g., stress,reaction to uncertainty, discomfort intolerance).Findings:Exploratory factor analyses (EFA) showed that both scales had a two-factor structure as inthe seminal article of Carleton et al. (2007). One item was removed from the IUS-12-H dueto crossloading on both factors. The cumulative explanatory variances were acceptable(0.53 for the IUS-12, 0.51 for the IUS-11-H). The factors of both scales were significantlypositively correlated (respectively, r = 0.61, r = 0.41, r = 0.41, r = 0.62) and positivelycorrelated with scales involving related constructs (e.g., Physicians' Reaction to UncertaintyScale). Besides, these factors were negatively correlated with the Need for Cognition Scale,and partially correlated with the Distress Intolerance Scale.Discussion:The IUS-12 and the IUS-11-H present good psychometric properties (i.e., internal structure,divergent validity and convergent validity) and can be used to assess individuals' level ofintolerance of uncertainty, and in the IUS-11-H version, health professionals' level ofintolerance of uncertainty.