The aim of this study was to determine the diagnostic and prognostic significance of ischemia modified albumin (IMA) levels in patients with Crimean-Congo hemorrhagic fever (CCHF). This retrospective study was conducted with patients with CCHF. IMA levels in patients with CCHF were determined using the rapid colorimetric method. IMA levels of CCHF patients were significantly higher compared with the control group (P=0.0001). At an IMA cut-off point of 0.555ABSU (absorbance units), sensitivity was 65.1%, specificity 82.5%, positive predictive values (PPV) 82.5%, and negative predictive values (NPV) 65.1%. IMA levels of patients with hemorrhage were significantly higher compared with patients without hemorrhage (P=0.005). IMA has been validated as both a new and sensitive ischemia and oxidative stress biomarker. In addition to its diagnostic significance, IMA investigated in CCHF patients at time of arrival may be an important marker with its prognostic role in determining in the early stage whether the disease will follow a hemorrhagic course. J. Med. Virol. 85:684688, 2013. (c) 2013 Wiley Periodicals, Inc.