Myeloid sarcoma is a rare tumor consisting of myeloid blasts that involve anatomic sites outside the bone marrow. Fatal prognosis is inevitable in patients with extramedullary relapse after hematopoietic stem cell transplantation (HSCT), and no standard treatments are available yet. We report the first case of extramedullary relapse after HSCT treated with a combination of daunorubicin, cytarabine, and cladribine (DAC) regimen plus radiotherapy and donor lymphocyte infusion (DLI). This treatment induced a new and durable remission in our patient. The favorable toxicity profile and the reduced cost make this combination worthy of further investigations.