Background/Aim. Virological testing is considered to be essential in the management of hepatitis C virus (HCV) infection in order to diagnose infection, and, most importantly, as a quide for treatment decisions and assess the virological response to antiviral therapy. The aim of this study was to determine the rate of a sustained virological response (SVR) and various factors associated with response rates in chronic hepatitis C infected patients treated with pegiinterferon alpha (PEGINF) and ribavirin (RBV) combination therapy. Methods. A total of 34 patients, treated with PEG-IFN and RBV were studied. Serum HCV-RNA was measured before the treatment, 12 weeks following the start of the therapy and 6 weeks after the treatment cessation. SVR was defined as undetectable serum HCV-RNA 6 months of post-treatment follow-up, virologic relapse (VR) as relapse of HCV-RNA during the post-treatment follow-up. Serum HCV-RNA was measured with the Cobas Amplicor test. Results. At the end of post-treatment follow-up 19 (55.8%) patients demonstrated a SVR. The majority of the patients were genotype 1 (27), and the other were genotype 3 (5 patients) and genotype 4 (2 patients). There was VR in 6 patients 6 months after the therapy. In 9 patients HCV-RNA was positive after 12 weeks. Conclusion. We demonstrated that patients with chronic HCV infection can be successfully treated with combination of PEG-INF and RBV. This result emphasizes also that post-treatment follow-up to identify patients with SVR or VR could be important.