Extramedullary plasmacytoma in the submandibular region is rare and on initial evaluation must be distinguished from multiple myeloma. The diagnostic evaluation includes appropriate radiological and pathological studies including immunohistochemistry. We report a case of extramedullary plasmacytoma in the submandibular gland. A review of the literature suggests that it has a good prognosis, if multiple myeloma is excluded. This patient was treated by surgical excision followed by radiotherapy.