Objective.Substantial empirical evidence has shown that intolerance of uncertainty is a central transdiagnostic fea-ture in psychopathology and it has been suggested to be a pain-related psychological factor contributing to the ex-perience of chronic pain. However, research in this area is virtually nonexistent. The objective of this study was to in-vestigate associations between pain severity, catastrophizing, and anxiety in people with chronic nononcologicalpain, while assuming that intolerance of uncertainty moderates these relationships.Methods.A convenience sampleof 188 individuals with nononcological chronic pain (157 women and 32 men) participated in the study. We investi-gated the moderated mediation of intolerance of uncertainty between anxiety and catastrophizing and between cata-strophizing and pain intensity.Results.The full moderated mediation model accounted for significant variance inpain intensity (R2¼0.148,P<.001). Intolerance of uncertainty significantly moderated the interaction between anxi-ety and catastrophizing (B¼0.039, SE¼0.012, 95% CI [0.015, 0.063]) and between catastrophizing and pain intensity(B¼-0.034, SE¼0.010, 95% CI [ 0.054, 0.014]). Anxiety and intolerance of uncertainty did not interact in predictingcatastrophizing, although an interaction effect was found between intolerance of uncertainty and catastrophizing inpredicting pain intensity.Conclusion.This study is the first to address the interrelationship of intolerance of uncer-tainty, catastrophizing, and anxiety in relation to perceived pain intensity. The current findings support intoleranceof uncertainty as a relevant psychological variable that is distinct from other relevant constructs in the setting ofpain research and treatment.