Anemia is an important and frequent secondary effect of the treatment with pegylated interferon and ribavirin in patients with chronic viral C hepatitis. Ribavirin produces more often hemolytic anemia, while pegylated interferon may determine medullary suppression. The level of hemoglobin beneath 10 g/dL is considered by most authors as being the reference level for anemia secondary to the antiviral treatment. Beneath this hemoglobin value it is recommended to reduce or to stop the treatment with ribavirin, to administer recombinant human erythropoietin or blood transfusion, based on the severity of the anemia. The growth rate of the serum erythropoietin in the first few weeks of treatment is correlated with the necessity of decreasing the doses or even to stop the treatment with ribavirin. The SVR (sustained viral response) rate of the patients is reduced when the ribavirin doses are reduced due to anemia.