Approximately 180 million individuals are chronically infected with hepatitis C, which is strongly associated with the development of cirrhosis, end-stage liver disease and hepatocellular carcinoma. Several virological tools (anti-HCV antibody assays, measurement of HCV-RNA, HCV-genotyping) are useful in management of hepatitis C infected patients. The primary goal of antiviral therapy in chronic hepatitis C is a sustained virological response (SVR). The HCV genotype should be determined in every patient considered for antiviral therapy because the currently recommended treatment duration and ribavirin doses differ among HCV genotypes. Exact subtyping might gain increased importance for future therapies with direct-acting antiviral agents (DAA) because of differences of antiviral activities and barriers to resistance among HCV subtypes. Monitoring HCV RNA by a highly sensitive assay (LOD ? 15 IU/ml) is the basis for management of response guided therapy of chronic hepatitis C with pegylated IFN plus ribavirin. Rules for early discontinuation of antiviral therapy in non-responders and determination of optimal treatment durations in virologic responders have been developed for application of individualized treatment strategies.