(1) Comparison effect of ribavirin alone and in combination with dexamethasone on clinical outcome of patients with severe form of haemorrhagic Crimean-Congo fever, (2) All patients with severe form of haemorrhagic Crimean-Congo fever C since July 2015 until April 2016 admitted in Boo-Ali infectious diseases hospital-Zahedan, 50 individual in two groups of 25 case, not blinded, block-randomized, single-center, phase 2,(3) The intervention group receive dexamethasone and ribavirin and control group are treated only with ribavirin. Then, mortality, length of hospital stay and the need for blood products used in both groups compared. (4) Inclusion criteria included having at least one criteria of severe form of the disease include severe reduction in platelet count (platelets less than 20,000); signs of bleeding as petechiae, ecchymosis and obvious bleeding; fibrinogen level less than or equal to 120 milligrams per deciliter; partial thromboplastin time more than or equal to 60 seconds; decreased level of consciousness. (5) Ribavirin 30 milligram per killogram for the first dose, then 16 milligram per killogram every 6 hours for 4 days, then 8 milligram per killogram every eight hours for six days as control group and ribavirin as noted in cintrol group in addition to dexamethasone 10 milligram per square meter body. (6) the rate of recovery-death mortality rate and blood products used in both groups recorded and compared.