Hepatitis C virus (HCV) is a common cause of chronic liver disease (CLD). Presently the standard regime comprises a combination of PEG-IFN and ribavirin. Sustained virologic response (SVR) is defined as the absence of HCV RNA in the serum six months after the end of treatment. With standard treatment, in patients with genotypel infections, SVR lies between 42% to 56%, whereas for genotypes 2 and 3 the SVR is from 76% to 82%. Thus, a large percentage of patients fail to achieve SVR even with improvised standard treatment. Such patients may be divided initially into relapsers and nonresponders. The decision to re-treat should be based on the presence of clinical, virological and histological factors that predict the possibility of successful outcome with further therapy. Both the type of previous therapy and previous response are very important factors in guiding re-treatment. The development of new therapeutic agents is critical for further improvement in the management of chronic hepatitis C as current therapeutic options have rather low efficacy in certain subgroups, such as those with HCV genotype 1 or patients with advanced liver disease, and most probably in nonresponders and relapsers. Moreover, pegylated IFNalpha and/or ribavirin are associated with frequent side effects and have a negative impact on the patient's quality of life. Therefore, the development of new effective and safe drugs is a matter of significant clinical importance.