All patients with hepatitis C virus (HCV) infection should be considered as candidates for antiviral therapy. In order to make decision whom to treat, it is necessary to evaluate the following parameters: stage of disease, comorbidity, patient age, contraindications and therapy risks. Therapy is strongly recommended in patients with acute infection, with elevated ALT levels, with normal ALT level and F > or = 2 METAVIR score, in non-responders to standard interferon monotherapy, in relapsers to antiviral therapy, in patients with compensated cirrhosis, and in hemodialysis patients. It is possible to treat patients with persistent normal ALT levels and without fibrosis, patients with HBV and HIV co-infection, patients with severe extrahepatic manifestations of HCV infection, and patients with liver transplant. Drug addicts and alcoholics can be treated after 6 months of abstinence, but also with supportive therapy. Therapy is not recommended in patients with fulminant hepatitis, kidney transplant recipients and pregnant women.