Auxiliary liver transplantation was originally started in Western countries in the form of heterotopic auxiliary liver transplantation for end-stage liver disease. It thereafter developed into the form of auxiliary partial orthotopic liver transplantation for acute liver failure. In Japan, where living-donor liver transplantation is the main mode of liver transplantation, auxiliary partial orthotopic liver transplantation was initially used for patients with metabolic liver diseases and has since developed into an effective solution for small-for-size living donor grafts. Although there has been a reported case of successful auxiliary partial orthotopic liver transplantation from a living donor for the treatment of acute liver failure, wide application of this technique is made difficult at present by such unsolved problems as functional competition, small graft size, severe clinical status, and toxic liver syndrome. Auxiliary partial orthotopic liver transplantation from a living donor is an established procedure for small-for-size living-donor grafts and metabolic liver diseases, and the future establishment of its successful application to cases of acute liver failure is anticipated.