Them aim of this study is to obtain information about the characteristics of the immune response, which causes damage in liver tissue, and its relation with the activity of the disease, serological and biochemical values in chronic viral hepatitis. In the study, needle biopsy of 62 cases diagnosed as chronic viral hepatitis and peripheral blood samples have been examined as flow cytometry and lymphocyte sub-types have alsol been analysed. And in the morphological evaluation, the hepatic activity has been defined by calculating the histological activity index. In addition, clinical, biochemical and serological data concerning cases has been found as well. In the analysis of flow cytometry, it is seen that T lymphoytes has been accumulated more in tissues comp ared to B lymphocytes and natural killer cells. No statistically significant difference has been noticed between the two groups concern in lymphocyte sub-types and rates of them seen in peripheral blood and tissue. But our data suggest that active histological disease in chronic hepatitis C infection may be associated with an increase in CD4/CD8 ratio and suggest that CD4 lymphocytes may play an important role in hepatic injury in these patients.