Chronic hepatitis has been in the focus of intense scientific research for decades. Recently, considerable progress and exciting new insights into pathogenesis and resulting therapeutic strategies have been made. Replication of hepatitis B and C viruses and details of life cycle in the host have been well characterised. 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 better understood by now 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 will 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 disusses in depth the novel findings in basic and clinical research.