The author has experienced recently a case of primary adenocarinoma of right middle ear cavity. A 43 year old man was admitted on April 4 1977 with complaints of right otalgia, hearing disturbance, right peripheral facial paralysis and dizziness, which have been developed gradually since 4 years before and more rapidly aggravated since 5 days prioly. The local findings of right middle ear showed that total defect of ear drum and bean size of hard mass was occupied in the middle ear cavity without ulceration of its surface and scanty purulent discharge was contained in the cavity. The external auditory canal was normal, the other region such as nasal cavity, paranasal sinuses, pharynx and nasopharynx were within normal limits. X-ray finding of the mastoid showed diffuse radiolucent sclerosing change on right mostoid, however no bony destruction was found. Operative finding revealed large bean size of tumor mass was found in superior half of the middle ear mucosa with moderate hard in consistency, the surface of the tumor was covered with almost normal membrane and well demarcated from normal mucosa. The mastoid cavity was edematous reddish granulation tissue and scanty mucopurulent discharge contained in it. There is no bony destruction was found macroscopically but small destruction was found microscopically on horizontal segment of facial canal and granulation tissue was covered on the destruction. The histopathological report received primary adenocarcinoma of the middle ear cavity. The post operative chemotherapy with bleomycin 0.25mg/kg twice a week intravenously for 60 days and every day topical administration of bleomycin solution for 40 days, and result was satisfactory.