A 64-year-old male consulted our clinic due to pancytopenia. Bone marrow appearance was consistent with multiple myeloma and an IgG-κ type M component was detected on electroimmuno-diffusion of urine. MP therapy (melphalan 2 mg/ day, prednisolone 10 mg/day) was started on an outpatient basis, but the pancytopenia worsened. The patient was then admitted to our hospital, and a course of Velcade therapy (bortezomib 2. 4 mg day 1, 4, 8, 11) was started. After a course of Velcade therapy, side effects such as gastrointestinal dysfunction appeared. A month after the disruption of the chomotherapy, the patient suddenly died. The autopsy report stated that the atrial blood showed 19, 200/μL of white blood cells and 39% of plasma cells, and a slight infiltration was found in liver, kidney and vessels. Two days before death, the blood picture showed no plasma cells. The cause of death was considered to be aggressive multiple myeloma.