Introduction: the purpose of this study was to determine the mediating role of emotion regulation difficulty in the relationship between Coronavirus anxiety and Health anxiety. Method: A descriptive-correlation research design with path analysis was applied. The statistical population were included all Iranian adults, from which 598 persons were selected by available sampling method. Participants were asked to fill Health anxiety Inventory (HAI-18), Corona Disease anxiety Scale (CDAS) and the Gratz and Roemer Difficulties in Emotion Regulation Scale (DERS). Data were analyzed using Pearson correlation and path analysis using SPSS and AMOS softwares. Results: The results showed well goodness of fit to the proposed model. In this model, coronavirus anxiety had a direct and significant effect on the emotion regulation difficulty, Coronavirus anxiety and emotion regulation difficulty had a direct and significant effect on Health anxiety; and emotion regulation difficulty also mediated significantly between coronavirus anxiety and Health anxiety. Conclusion: Coronavirus anxiety and emotion regulation difficulty had direct and significant effect on Health anxiety. Emotion regulation difficulty could mediating between coronavirus anxiety and Health anxiety as well.