A 54-year-old man diagnosed with IgD myeloma (stage IIIA) in complete remission (CR) received peripheral blood stem cell transplantation (PBSCT) twice with an interval of 4 months using high-dose melphalan 200   mg/m 2. However 9 months after the second PBSCT, he was readmitted because of lumbago, lower left hemiparesis, speech disturbance and left facial nerve palsy. A lumbar puncture revealed myeloma cells in the cerebrospinal fluid (CSF). The patient did not respond to any salvage chemotherapy and died of sepsis 27 months after the initial diagnosis. The findings in this patient suggest that another treatment modality including prophylactic intrathecal injection of an anti-cancer drug as well as allogeneic cell therapy is probably necessary in patients with high-risk IgD myeloma.