Extramedullary plasmacytoma is rare tumor of plasma cell tumor, which involve soft tissue without any signs of systemic spread and occurs predominantly in the head and neck, especially the nasal cavity and the paranasal sinuses. Ten to twenty percent of extramedullary plasmacytoma have regional lymph metastasis at the time of diagnosis and approximately one third of patients with extramedullary plasmacytoma will subsequently develop multiple myeloma during long-term follow-up. Primary treatment modality is moderate-dose radiation and surgery is rarely used. Extramedullary plasmacytoma has good prognosis, but requires long-term systemic evaluation and follow-up. We report a case of extramedullary plasmacytoma of the sinonasal cavity with a review of literature.