Introduction: Myocarditis is a rare extraintestinal cardiac manifestation of IBD. It is more commonly reported in Ulcerative Colitis than in Crohn's disease (CD) and consequently not frequently reported. Moreover, the prevalence of myocarditis in CD patients on immunosuppressive and immunomodulatory therapy is not well known. Our study aims to assess the prevalence of myocarditis and the effect of immune-modifying therapy in CD. Methods: In multi-institutional database (Explorys Inc, Cleveland, OH) which includes electronic health record data from 26 major integrated US healthcare systems. Based on the Systematized Nomenclature of Medicine – Clinical Terms (SNOMED-CT), we identified all patients (age >18 years) with a concomitant diagnosis of myocarditis and CD between 1999 to 2022. We investigated the prevalence of myocarditis in CD compared to patients with no IBD. Also, we compared the prevalence between CD patients with and without immune-modifying agents. Results: Of the 70, 301,380 individuals in the database from 1999 to present, we identified 249,300 (0.3%) patients with CD, of whom 40,840 (16.4%) patients received anti-TNFs. CD patients were 59.4% females, 76% Caucasian, and 70% in 18-65 years age group. The prevalence of myocarditis was 0.12% for CD compared to 0.04% in individuals without IBD, p< 0.001. Compared to the general population, patients with CD had higher association risk of myocarditis diagnosis [OR: 3.33, p< 0.0001]. Among CD, predictors of having myocarditis included being elderly ( >65 y/o), African American, smokers and has history of type 2 diabetes (P< 0.0001). The prevalence of myocarditis was significantly lower CD patients on anti-TNF agents [OR: 0.08, p < 0.0001], and thiopurines [OR: 0.11, p < 0.0001] whereas methotrexate and 5-aminosalicylates (5-ASA) had higher rates [OR: 2.78, p < 0.0001] and [OR: 1.63, p =0.0001], respectively. No significant effect was noted with Vedolizumab [OR: 1.30, P= 0.4103] (Figure). Conclusion: In this large database, we found a higher risk association between CD and myocarditis. Anti-TNF agents and thiopurines were less likely to be associated with myocarditis, while methotrexate and 5-ASA were more likely to be associated with myocarditis in CD. The difference in the association between immune-modifying agents is unclear. Hence, further prospective studies are required to evaluate this association. Our findings may have significant implications for patients with cardiac risk factors and underlying myocardial dysfunction.Figure 1.: Overall Risk and Predictors of Myocarditis Among Crohn's disease. Univariate analysis used to calculate OR. OR; odds ratio, CI confidence interval. Anti-TNF; anti-tumor necrosis factor. 5-ASA; mesalamine.