The aim of 36 months follow up study was to assess the safety and efficacy of Filgrastim (Neupogen) for preventing neutropenia and bacterial infection during combination therapy of chronic HCV infection with pegilated interferon alfa and ribavirin. Study enrolled 64 patients with chronic active hepatitis C, aged 20-65. Among them 49 were male and 15 female). Among 64 patients: 5 patients had HCV genotype 1a, 24 patients HCV genotype 1b, 17 patients HCV genotype 2a/2c and 18 patients HCV genotype 3a. Treatment regimen for chronic hepatitis C patients was as follows: Pegylated interferon alfa 2a (Pegasys) 180 micro kg or alfa 2b (PegIntron) 1,5 micro g/kg. and ribavirin (RBV). RBV daily dose was adjusted by body weight- 1000/1200 mg. Treatment duration was 48 weeks for HCV genotype 1 patient and 24 weeks for HCV non 1 genotype accordingly. The patients were divided into two groups: 29 patients (1st group) besides combination antiviral therapy (pegilated interferon alfa plus ribavirin) systematically received Filgrastim and other 35 patients (2nd group) - same antiviral therapy without administration of Filgrastim. Selection of patients was performed by computerized randomization method. HCV antibodies were detected by ELISA and RIBA. HCV RNA by Real time PCR. HCV genotype- by Inno-Lipa. Among 2nd group 35 patients (without Filgrastim administration) during antiviral therapy 8 patients (22.8%) developed different bacterial infections.(3 patients- urinary tract infection, 2 patients- pneumonia, 1 patient- bronchitis, 1 patients - sinusitis and 1 patient-gingivitis/stomatitis). 7 patients required interferon dose modification (dose reduction) and in 5 patients treatment stopped due to severe neutropenia. Among 1st group patients (with filgrastim administration) only one patient developed bacterial infection (urinary tract infection). None of patients, due to neutropenia, required neither stoppage of therapy, nor interferon dose reduction. The quality of life of 1st group patients was better in comparison of 2nd group patients. Filgrastim was safe and effective for prevention neutropenia and bacterial infections in Hepatitis C patients with Peg-INF/RBV combination antiviral therapy. Filgrastim was well tolerated by patients. It gives possibility to maintain interferon dose during treatment period and significantly improves the patient's quality of live.