A 77-year-old man was referred with a 4-month history of hearing impairment and ear fullness of the left ear. Otoscopic examination revealed an effusion in the left middle ear, and nasal endoscopic examination revealed a dark polypoid lesion at the opening of the left Eustachian tube. In addition to the lesion of the Eustachian tube, a dark mucosal lesion was seen at the posterior choana and the posterior end of the nasal septum. Endoscopic biopsy was done and pathologic result was consistent with malignant melanoma. Wide surgical excision with postoperative radiotherapy was performed; multiple metastases were detected 4 months after the treatment. Mucosal melanoma originating from nasopharynx was extremely rare, but careful examination of nasopharyngeal area should be considered when the patient presents with unilateral middle ear effusion, especially in older age.