To estimate the prevalence and clinical significance of leukopenia and neutropenia in patients with chronic hepatits C, to analyze the impact of different regimens of antiviral therapy by standart or induction doses of pegylated interferon alpha-2a (PegIFNalpha-2a) to optimize curative measures.24 patients with genotype 1 HCV and different therapeutic regimens of PegIFNalpha-2a were investigated with analysis of kinetics and prevalence of leukopenia and neutropenia.On an average 66,7% patients meet neutropenia during antiviral therapy, and 37,5% and 16,7% among them was the moderate and severe grade accordingly. The major prevalence of leukopenia and neutropenia was evidenced between 12 and 24 weeks of antiviral therapy, the marked severity of neutropenia was noted.It was no correlation between the prevalence of leukopenia and neutropenia and the induction treatment regimens of PegIFNalpha-2a; the tendency for more severity in patients with advanced fibrosis and cirrhosis was detected. It was no infection complications during the therapy observed so it may be provided with full doses of PegIFNalpha-2a in case of mild and moderate grades of leukopenia and neutropenia.