Background. The presence of lymphocytes within the liver parenchyma is related to immunologically mediated liver damage in chronic hepatitis C. The aim of the study was to make histological, histochemical, and immunocytochemical assessment of liver biopsy specimens in patients with chronic hepatitis C virus (HCV) infection. Methods. Biopsy specimens of 20 patients with chronic HCV disease were analyzed, using standard staining procedures to verify histologic liver lesions, as well as immunoenzymatic staining with monoclonal antibodies to detect CD4+ T-lymphocytes, B-lymphocytes, and macrophages. Results. Micromorphologic characteristics of chronic active viral hepatitis C were present in all the patients, differing, hower, by the level of their activity. Dominant changes were found within the portal space, consisting of mononuclear lympho-plasmocytic infiltration and macrophages. Immunocytochemical investigation of mononuclear and macrophageal infiltration showed the correlation between micromorphological findings and the degree of the activity. Conclusion. The presence of lymphocytic and macrophageal infiltration within the hepatic tissue directly correlated with the intensity of the liver damage. Analysis of the population of cellular infiltrate in the liver together with the monitoring of viremia level and the level of hepatocyte necrosis, could be useful tools for elucidation of the pathogenesis of chronic hepatitis C.