Abstract: Solitary plasmacytoma of the skull is very rare, and only a few cases have been reported in the literature. It remains controversial whether solitary plasmacytoma of the skull is essentially identical with solitary plasmacytoma of bone or not. Solitary plasmacytoma of bone including solitary plasmacytoma of the skull is characterized by a radiologically solitary bone lesion, neoplastic plasma cells in the biopsy specimen, fewer than 5% plasma cells in bone marrow, <2.0 g/dl monoclonal protein in the serum when present and negative urine test for Bence Jones protein (monoclonal light chain). We report one case of a 70-year-old woman who referred to our hospital because of a progressive left parietal swelling. On clinical examination, a painless large soft mass in the right parietal region was observed. Computed tomography revealed an extra-axial mass in the in the left frontoparietal region. The lesion was totally excised despite the bleeding tendency. Histology disclosed the presence of a plasmacytoma. On follow-up examination, 7 months later no tumor recurrence or evidence of multiple myeloma was detected.