Aregeneratoric anemia (AA) occurs rarely after ABO-incompatible allogeneic peripheral blood stem cell transplantation (alloPBSCT), and its management is generally difficult. Here, we present a 31-year-old white man with myelodysplastic syndrome who developed AA after receiving stem cells from his human leukocyte antigen (HLA) identical, but ABO-incompatible sibling. Because his anti-A antibody titers were high, therapy with conventional doses of erythropoietin and prednisolone failed to treat the AA. Following 8 cycles of plasma exchange and higher doses of erythropoietin and prednisolone as well as danazol administration, anti-A titers decreased, and his anemia improved significantly. In conclusion, to treat and obtain a low titer of antibodies in a patient with AA following an ABO-incompatible alloPBSCT, higher doses of erythopoietin and corticosteroids associated with plasma exchange have to be used.