The last years of the 20th century saw an increasing need for transplantation, but the number of donor livers available increased only slightly, despite intensive public relations activities. Alternative concepts in the field of transplantation, for instance the transplantation of living donor organs or the splitting of organs, are urgently required, to safeguard the treatment of patients with severe liver disease. The development and clinical application of cell therapy for patients with liver disease could present a significant enhancement of the therapeutic options. The aim of such cell therapy is to repair or improve the biological function of the chronically and acutely damaged liver. Even though systematic trials are not available, individual case reports and small series already show promising clinical results. Concepts of cell therapy for liver diseases based on the use of primary hepatocytes have recently been considerably extended through new data on the biology of stem cells. The adult haematopoetic stem cell as a pool for hepatocyte grafts - what would be the perspectives for the clinical application? This book is the proceedings of the Falk Symposium No. 126 on "Hepatocyte Transplantation" (Progress in Gastroenterology and Hepatology Part III) held in Hannover, Germany, October 2-3, 2001, and is a forum for basic research, but also for questions concerning clinical applications in the field of hepatocyte transplantation.