Schneiderian papillomas are papillary lesions of the nasal cavity paranasal sinuses that arise from the Schneiderian membrane, a membrane of ectodermal origin embryologically derived from the nasal placodes. This membrane is characterized by transitional type epithelium, similar to bladder urothelium, with admixed microcysts or mucin droplets. It has a tendency to recur after removal and transform into malignancy even though rare. Total 27 cases of Schneiderian papillomas were examined in the Chosun University medical college, which were collected from 1978 to 1986. The results obtained were as follows: 1) There were 19 male and 8 female patients, and mean age at diagnosis was 50.5+/-12.0 (SD) year (27-74 years). 2) Nasal obstruction or perception of nasal mass was the most common presenting symptom; Mean duration of symptoms was 25.8+/-15.0 (SD) month (4-48 months). 3) Numbers of papillomas had predominantly endophytic (inverted, n=17) and predominantly exophytic (fungiofrom n=6) patients, and four had mixed pattern. 4) In 27 patients, recurrences developed in 9, local invasion in one (with an inverted papilloma), and epidermoid carcinoma in one (with an inverted papilloma).