We report a rare case of extramedullary plasmacytoma of the nasal septum in a 65-year-old woman. She presented with a 2-month history of left-sided nasal obstruction and intermittent blood-tinged nasal crusting. Nasal endoscopy revealed that a dark-red mass had arisen from the nasal septum; no evidence of invasion to adjacent tissues was seen. A biopsy specimen was diagnosed as a plasmacytoma (kappa light chain'type). Serum and urine electrophoresis failed to detect any myeloma component or Bence Jones protein. All other screening tests to rule out multiple myeloma were negative. These findings confirmed the diagnosis of extramedullary plasmacytoma. The mass was completely removed via an endoscopic approach. No recurrence was noted at the 2-year follow-up.