Crimean-Congo Hemorrhagic Fever (CCHF) is a disease transmitted by the Crimean-Congo hemorrhagic fever virus (CCHFV), characterized by severe fever and hemorrhage and with a reported fatality level of 3-30%. Cerebral hemorrhage, gastrointestinal hemorrhage, severe anemia, shock, myocardial infarction, pulmonary edema, and pleural effusion may be seen as causes of death. Cardiac troponin T (cTn-T) is a biochemical marker with high sensitivity and specificity in myocardial injury. The purpose of this study was to determine the prognostic significance of serum troponin T levels in CCHF patients. Patients hospitalized with a diagnosis of CCHF and whose serum cTn-T was investigated were examined retrospectively. Patients were divided into two groups on the basis of presence or absence of hemorrhage. Data were subjected to statistical analysis. One hundred thirty-five CCHF patients and 72 control subjects were included. Hemorrhage was present in 48 (35.6%) patients. Mean serum cTn-T level was 17.3 +/- 28.0 ng/L in the patients with hemorrhage, 9.98 +/- 5.97 ng/L in the non-hemorrhage patients (P = 0.001) and 6.6P = 2.6 ng/L in the control samples (P < 0.001). At a cTn-T level cut-off point of 9 ng/L, area under the ROC curve was 0.797 (95% CI: 0.730-0.854), sensitivity 83.0%, specificity 87.5%, PPD 95.7%, and NPV 60.3%. At logistic regression analysis, a rise in cTn-T level above 14 ng/L increased the probability of hemorrhage in CCHF patients approximately threefold. An increased troponin T level may be a prognostic risk factor for hemorrhage in CCHF patients. This marker should therefore be borne in mind in determining treatment strategy in these patients. (C) 2015 Wiley Periodicals, Inc.