Plasmacytoma is a rare malignant neoplasm in the head and neck region and comprises approximately 3% of all plasma cell tumors. This lesion is a unifocal, monoclonal, neoplastic proliferation of plasma cells that usually arises within the bone. Infrequently, it is observed in soft tissue, in which case, the term extramedullary plasmacytoma is used. Approximately 80-90% of extramedullary plasmacytomas involve the mucos-Associated-Lymphoid Tissue of the upper airways with 75% of these involving the nasal and paranasal regions. The plasmacytoma is usually detected in adult males, with an average age at diagnosis of 55 years. The male-to-female ratio is 3:1.Radiographically, the lesion may be seen as a well-defined, unilocularradioluceny with no evidence of a sclerotic border. Some investigators believe that this lesion represents the least aggressive part of the spectrum of plasma cell neoplasms that extend to multiple myeloma.Therefore, plasma cytoma is believed to have clinical importance. We report a case of extramedullary plasmacytoma in the right maxillary sinus of a 59-year-old male with review of the relevant literature.