Hepatitis B (HBV) and C (HCV) viruses differ both in viral structure and in natural history of chronic infection. However, they seem to share, although to a different extent, some characteristics, like the possibility to infect not only hepatic but also lymphatic cells and to associate with some hepatic and/or extrahepatic disorders of an autoimmune and/or lymphoproliferative nature. These characteristics have been more widely studied in the case of chronic HCV infection, where they are more evident, but they have been described also in the case of HBV infection.