Chronic hepatitis has been the focus of intense scientific research for decades and considerable progress and new insights into its pathogenesis and resulting therapeutic strategies have been made. Replication of hepatitis B and C viruses and details of its life cycle in the host have been well characterized. Immunology in general and immunopathology of the liver in viral and autoimmune hepatitis have shown more specific mechanisms of host defence and new models of autoimmune aggression have been developed. The role of apoptosis in liver damage is now well appreciated and has been analyzed precisely. Essential steps of fibrogenesis as a consequence of chronic liver damage are now better understood and new strategies for its prevention have evolved. Chronic hepatitis is the leading cause of liver cell carcinoma, the molecular basis of which has been more clearly elucidated. This increasing knowledge should provide a sound basis for more effective therapy in chronic hepatitis and its life-threatening consequences. This book, the proceedings of the Falk Workshop on Chronic Hepatitis, held in Cologne, Germany, on January 27-28, 2000, brings together experts from different fields of research such as virology, immunology, pathology, cell and molecular biology, as well as clinical medicine, and discusses in depth the novel findings in basic and clinical research.