Crimean–Congo hemorrhagic fever (CCHF) is a viral disease. Symptoms of CCHF may include fever, muscle pains, headache, vomiting, diarrhea, and bleeding into the skin. Onset of symptoms is less than two weeks following exposure. Complications may include liver failure. In those who survive, recovery generally occurs around two weeks after onset.

The CCHF virus is typically spread by tick bites or close contact with the blood, secretions, organs or other bodily fluids of infected persons or animals. Groups that are at high risk of infection are farmers and those who work in slaughterhouses. The virus can also spread between people via body fluids. Diagnosis can be made by detecting antibodies, the virus's RNA, or viral proteins (antigens). It is a type of viral hemorrhagic fever.

There are no FDA- or WHO-approved therapeutics for CCHF. Prevention involves avoiding tick bites, using safe practices in meat processing plants, and observing universal healthcare precautions. A vaccine is not commercially available. Treatment is typically with supportive care. The medication ribavirin may also help.

CCHF cases are observed in a wide geographic range including Africa, Russia, the Balkans, the Middle East, and Asia. Typically small outbreaks are seen in areas where the virus is endemic. In 2013 Iran, Russia, Turkey, and Uzbekistan documented more than 50 cases. The fatality rate is typically between 10 and 40%, though fatalities as high as 80% have been observed in some outbreaks. The virus was first observed in Crimea in the 1940s and was later identified as the same agent of what had been called Congo Hemorrhagic Fever.

In the past 20 years, CCHF outbreaks have reported in Eastern Europe, particularly in the former Soviet Union, throughout the Mediterranean, in northwestern China, central Asia, southern Europe, Africa, the Middle East, and the Indian subcontinent. CCHF is on WHO’s priority list for Research and Development and the US National Institute of Allergy and Infectious Diseases (NIH/NIAID) priority A list, as a disease posing the highest level of risk to national security and public health.