In Japan, liver transplantation from brain dead donors has not yet started. The authors present the first report of a clinical experience with a child with fulminant hepatic failure in whom the combined treatment of plasma exchange and continuous hemodiafiltration using a high-performance polymethylmethacrylate membrane was used successfully to sustain life for a period of as long as 54 days before liver transplantation from a living donor could be performed. The combination of plasma exchange and continuous hemodiafiltration appeared to maintain blood coagulation and level of consciousness effectively. Although the combined use of plasma exchange and continuous hemodiafiltration is still unsatisfactory as an artificial liver support, the authors suggest that this technique may be useful to support the life of a child who awaits liver transplantation.