Purpose: This study was conducted to evaluate the correlations among pulmonary contusion severity, trauma score and cardiac troponin I (cTnI) level. Methods: We prospectively evaluated patients with multiple injuries who had been admitted to the emergency department (ED) from July 2007 to July 2008. We first measured the total creatinine kinase (CK), the MB fraction of CK (CK-MB), TnI, and myoglobin within 2 hours after the injury. We then checked the electrocardiogram, x-ray, and computed tomography (CT) results. Finally, we assessed the injuries as variables and then compared the results for patients with elevated TnI levels (group A) and patients whose TnI levels fell within the normal range (group B). Results: Eighty-six of the 92 patients admitted to the ED were enrolled. The pulmonary contusion score (PCS) was well correlated with $PaO_2/FiO_2$. TnI levels were correlated with PCS. When TnI levels were above 0.86 ng/ml, the mortality was estimated with 100% sensitivity and 86.1% specificity. Conclusion: Pulmonary contusion severity is correlated with TnI level. When the PCS is high and the cTnI level is elevated in multiple-injury patients, we recommend continuous cardiac monitoring and further evaluation