From March 1958 to October 1984, 10 patients with cylindroma (cystic adenoid epithelioma) arising in the nasopharynx were treated in our hospital. The presenting symptoms of these patients ranged in duration for 2 weeks to 8 years, with an average of 25 months. Eighty percent of the patients had destruction of the base of skull and 60% had cranial nerve involvement. Of these 10 patients, two had Stage II disease, two had Stage III, and six had Stage IV. Response was seen in this tumor at tissue doses between 5000–8000 rad. Of the seven patients at risk for 5 years, 86% survived, yet 36% of the patients died of tumor between the fifth to tenth year. Fifty percent of the patients lived beyond 10 years. Based on this experience, a dose of more than 8000 rad is advised for the primary lesion. For the neck region, radiation is indicated only when there are lymph node metastases; prophylactic radiation of the neck is not necessary. Local recurrence or single distant metastasis is amenable to radiation therapy. Among the six patients who failed in the course of follow-up, three had local recurrences, two had pulmonary metastases, and one died of cerebral vascular accident.