The bcl-2 gene is involved in the regulation of programmed cell death by providing a survival advantage to rapidly proliferating cells. This study investigates bcl-2 protein expression in liver biopsies with acute or chronic viral hepatitis B (HBV) or C(HCV). The study comprised 60 liver biopsies with hepatitis B or C. These included 10 biopsies from cases with acute lobular hepatitis (ALH), and 50 with chronic hepatitis (CH). In addition, 10 liver biopsies were used as controls. In CH cases, HAI grade ranged from 3/18 to 15/18, and stage from 1 to 6 (6HBV/8HCV). Immunohistochemical bcl-2 expression was assessed using the streptavidin-biotin method and the presence of apoptotic cells was evaluated by TUNEL method. Immunohistochemical and in situ hybridization (TUNEL) results were expressed following morphometric analysis. In CH cases, bcl-2 was detected in portal and intralobular lymphocytes, and in cholangiolar epithelial cells of the interface area. In ALH and control cases, bcl-2 was expressed only in lymphocytes. Lymphocytic bcl-2 expression was correlated directly with categories A, C and D of HAI (P < 0.001), whereas the degree of fibrosis was reversibly correlated to bcl-2 expression. In conclusion, in cases of chronic hepatitis, bcl-2 expression in cholangioles of interface area suggests that this oncoprotein may be involved in regulation of growth of these epithelial cells.