Liver transplantation is the only curative therapy for patients with end-stage liver disease. The high success rate and the increasing demand for the transplantation sometimes calls for ABO-compatible but nonidentical blood group orthotopic liver transplantation (OLT), which affords the opportunity to the production of antibody to red blood cells. Hemolytic anemia usually occurs 1 to 2 weeks after transplantation. Although mild in most patients, it can be life-threatening. Until now, a few cases showing hemolytic anemia due to donor ABO antibody formation after ABO-nonidentical OLT have been reported. In the reported cases of hemolytic anemia, most ABO-nonidentical OLT cases were O-to-A, but few reports are available on this subject with O-to-B ABO-nonidentical OLT. Herein, we report the experience with hemolysis after ABO-nonidentical OLT in a group O donor into a group B recipient and the successful treatment with transfusion of washed group O red blood cells and 60 mg dose of prednisolone for 3 days.