A 56-year-old man with left anterior chest pain showed two well-defined tumors in the left anterior chest wall and left parietal region. A large osteolytic lesion in the parietal bone and several punched-out lesions in the temporal bone were revealed by a skull X-ray examination. He showed monoclonal gammopathy (IgG, kappa type) and Bence Jones proteinuria, but no proliferation of plasma cells was observed in the bone marrow. The tissue specimens from both lesions consisted of abnormal plasma cells, indicating plasmacytoma. Although a bulky intracranial plasmacytoma was present, the patient did not exhibit intracranial hypertensive symptoms, or neurological abnormalities.