A 37-year-old man with moderately severe hemophilia A (factor VIII of 1.2%), who had a normal liver without liver cirrhosis or hepatocellular carcinoma, was referred to our liver transplantation (LT) team. LT was planned for sufficient coagulation factor level maintenance and prophylaxis against future hemorrhagic complications. The donor was the patient's 35-year-old wife, who was nonhemophilic. We performed an auxiliary partial orthotopic liver transplantation (APOLT) with the approval of the Institutional Ethics Committee. A left partial liver graft taken from the donor was orthotopically transplanted to the recipient after resection of the native left hemiliver while preserving the native right lobe. After surgery, the patient tolerated the procedure, and tacrolimus was used to maintained immunosuppression. In this recipient, factor VIII activity significantly increased soon after the APOLT, and has been maintained at >20% without any further bleeding episodes for the past 74 months since the procedure. This finding suggests that APOLT may be an effective alternative treatment for patients with hemophilia A.