Malignant melanoma arising from the mucous membrane of the nose and paranasal sinuses are characterized by their rapid spread and poor prognosis. This form of malignancy is fortunately rare in the nose and paranasal sinuses compared to those of other parts of the body. Slightly more than 200 cases have been reported mostly in western literatures and a few cases of report for malignant melanoma of the nasal cavity and paranasal sinuses in Korea up to date. The authors hare experienced recently a case of primary malignant melanoma originated in the lateral wall of the left nasal cavity and extended into the posterior ethmoidal cells. The patient who was treated by wide excision of the tumor and nasal mucosa through lateral rhinotomy and postoperative irradiation by Co 60 showed relatively improving result until present time. Here, the authors report the patient's clinical course and brief review of the literatures of malignant melanoma originating the nasal cavity and paranasal sinuses.