Crimean-Congo hemorrhagic fever (CCHF), caused by infection with CCHF virus (CCHFV), is viral hemorrhagic fever with high case fatality rate. CCHFV is classified to Family Bunyaviridae, Genus Nairovirus. CCHF is endemic to Africa, Eastern Europe, the Middle East, central Asia, and southern Asia. CCHFV is maintained in nature in several spe- cies of ticks (Hyalomma and Ixodes species) and mammals. Humans are infected with CCHFV by tick-bite or direct contact with viremic animals such as sheep. The CCHF-endemic re- gions are relatively economically disadvantaged areas, therefore CCHF is considered to be one of the neglected infectious diseases. The pathophysiology has not yet been clarified fully. It is necessary to clarify the pathophysiology of CCHF and to develop specific antiviral drug- based therapy and vaccines, which might be effective in confering protection against CCHFV infections in the near future, because CCHF outbreaks continue to occur in the endemic re- gions.