An adult woman developed polymorphic post-transplant lymphoproliferative disorder (PTLD) 58 months after unrelated cord blood transplantation. She was treated successfully with chemotherapy and radiation therapy but presented with lymphadenopathy and splenomegaly 74 months after transplantation. A lymph node biopsy confirmed the diagnosis of nodular sclerosis type Hodgkin lymphoma (classical Hodgkin lymphoma [CHL]-type PTLD). After salvage therapy and hematopoietic stem cell harvesting, she was subsequently treated with consolidative high-dose chemotherapy with melphalan followed by stem cell rescue, which resulted in durable remission. High-dose chemotherapy using stem cell rescue has potential as a therapeutic option for subsequent CHL-type PTLD.