Background: Endomyocardial biopsy often fails to reveal myocardial injury and inflammation in clinically suspected myocarditis. Levels of serum cardiac troponin T (cTnT) are elevated in myocardial injury, even in the absence of histological signs of myocarditis. We measured serum cTnT levels, histology and viral titers in hearts at various stages of murine coxsackieviral B3 (CVB3) myocarditis, to investigate their correlation during the course of viral myocarditis. Methods: Balb/C female mice were infected intraperitoneally with 10 ⁴ pfu of two different CVB3 variants, myocarditis strain (H3) and amyocarditic variant of CVB3-H3 (10A1). Serum and hearts were collected at various time points. To identify myocyte damage in the hearts, Evans blue dye was injected intraperitoneally at 12 hours before harvesting hearts. The degree of inflammation was analyzed by H&E staining. In the cryosection, CVB3 infected myocytes were immunostained with an anti-enteroviral VP1 antibody. Serum cTnT level was measured by ELISA. Results: Viable virus titers in H3 hearts were higher than in 10A1 hearts, peaked 3 days after infection, and decreased at day 7, and no viable virus at day 14, in the heart infected with both viruses. Myocardial inflammation was peaked at day 7, and decreased markedly at day 14 in H3 hearts. Scanty inflammation was observed in 10A1 hearts. Evans blue uptake under fluorescent microscopy was observed from day 3 and peaked at day 7, and it was co-localized with the infected myocytes. Individual serum cTnT levels were significantly increased on day 3 (7.37짹1.47, 1.15짹0.35 ng/ml), persisted to day 7 (0.73짹0.08, 0.47짹0.13), and normalized at day 14 in H3 and 10A1 hearts, respectively. Serum cTnT levels were positively correlated with viral titers in the heart (r = 0.746, p < 0.01), but not with the degrees of inflammation. Conclusions: The elevated serum cTnT level provides evidence of myocardial injury even in the absence of inflammation in the histology after viral infection, therefore, in clinical situations, the additional virus detection methods are needed for the accurate etiologic diagnosis of viral myocarditis in the clinically suspected myocarditis.