About 70% of HCV infection fail to resolve spontaneously and progress to chronic hepatitis C, eventually to cirrhosis and HCC. Many studies have demonstrated that clinical manifestation and the outcome of HCV infection are negatively influenced by a variety of cofactors and comorbidities. Moreover many of these cofactors often reduce the chance of achieving a sustained virological response (SVR) with only available combination therapy with pegylated interferon-alpha2 (PEG-IFN) and ribavirine (RBV). Dose modification of both currently licensed drugs for treatment of HCV infection and variations of treatment duration are the most discussed strategies to optimized the therapy, particulary in patients infected by genotype 1 HCV. Tailoring the duration of peginterferon/ribavirine therapy to HCV kinetics is useful to optimize the results of therapy.