Crimean-Congo hemorrhagic fever (CCHF) is known to be associated with cardiac damage. Brain type natriuretic peptide (BNP) is secreted from stressed myocardium.This study investigated that BNP levels in CCHF and its association with clinical course of disease.Consecutive CCHF diagnosis confirmed patients were enrolled to the study. Results of patients were compared with age-sex-matched healthy volunteers. Blood samples for BNP levels were collected from the patients during emergency room applications. Mortality, hospitalization duration and other disease severity predictors (thrombocyte count, hemoglobin, white blood cell count, alanine aminotransferase, aspartate aminotransferase, prothrombin time, lactate dehydrogenase, international normalized ratio, activated partial thromboplastin time) were recorded. These parameters' correlations with BNP levels were analyzed.Forty-three CCHF patients and 28 control subjects recruited to the study. Groups were similar for age and gender. There was no mortality. Levels of BNP were found to be significantly higher in patients than control subjects (100.4±45.4 vs. 78.0±40.4, P=0.033). But BNP levels were not correlated with duration of hospitalization and disease severity predictors (P > 0.05).This study showed that BNP levels are modestly increased in CCHF but this increase does not correlated with disease severity predictors.