The fatality rate of Crimean-Congo haemorrhagic fever (CCHF) disease has been reported as 5.4-80%. In this prospective study our aim was to evaluate the clinical and laboratory predictors of fatality in patients with CCHF. Among probable CCHF patients admitted to our clinic between 2005 and 2008, patients with positive IgM antibodies and/or polymerase chain reaction for CCHF virus were included in the study. To determine the predictors of fatality, we compared epidemiological, clinical and laboratory findings of the fatal cases with survivors. Ninety-three confirmed CCHF patients were included in the study; 56 (60.2%) of them were female. Mean patient age was 48.4+/-17.7 y and mean hospital stay was 7.9+/-3.0 days. Five patients died (5.4%). The rates of haemorrhage, diarrhoea and confusion were higher in fatal cases compared with non-fatal cases (p<0.05). Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, lactate dehydrogenase (LDH), and C-reactive protein levels were higher in fatal cases; the international normalized ratio (INR) and activated partial thromboplastin time (aPTT) were longer and mean platelet counts were lower (p<0.05). By multivariate analysis, diarrhoea, melena, haematemesis, haematuria, elevated ALT and LDH, and prolongation of aPTT were independent clinical and laboratory predictors associated with fatality. We suggest that for patients who have diarrhoea, melena, haematemesis, haematuria, elevated AST and LDH, and a prolonged aPTT, physicians should be aware of the high fatality risk.