The study aimed at localizing TNF-alpha, IL-1alpha, IL-6 at light and electron microscope levels in patients with chronic hepatitis C, using the immunocytochemical techniques in biopsy material from patients with chronic hepatitis C and at comparing the expression of the cytokines with histopathological changes. Our studies demonstrated an augmented expression of all cytokines in liver biopsies in chronic hepatitis C, in comparison with respective values, obtained in control biopsy material. The highest expression of the cytokines was observed in hepatocytes. That was confirmed by electron microscopy, which demonstrated the cytokines mainly in altered ER cisterns and in the cytoplasm. In children, the expression of IL-1alpha was negatively correlated with staging, while in adult patients; the staging was positively correlated with the expression of TNF-alpha. The new element involves demonstration of cellular and subcellular expression of TNF-alpha, IL-1alpha and IL-6 in hepatocytes in in vivo infection.