A 3-year-old boy with Hodgkin lymphoma relapsed only 2 months after completion of first-line therapy. He received reduced-intensity conditioning and allogeneic hematopoietic stem cell transplantation (RIC allo-HSCT), but relapsed again. To treat the second relapse, donor lymphocyte infusions were performed four times. He showed no evidence of disease and his quality of life was maintained for 500 days after stem cell transplant. However, his condition worsened and he died 3 years and 3 months after onset. In high-risk patients fully intolerant to myeloablative regimens, RIC allo-HSCT followed by subsequent donor lymphocyte infusions must be considered an effective therapeutic approach.