Nasal polyp is a benign neoplasm, one of diseases commonly encountered in otolaryngologic clinics. The etiology and pathogenesis of nasal polyps, however, are not fully uncovered despite many previous studies. Chronic infection and allergy are known to be the two major etiologic factors of nasal polyps. In addition to infection or allergy of the nose and the paranasal sinuses, vasomotor disturbance, autonomic dysfunction, endocrine abnormalities and mechanical factors seem to contribute to the development of nasal polyps in combined ways. The purpose of this study is to analyze the clinical manifestations and histopathology of nasal polyps. A total of 85 patients with nasal polyps in Chuncheon area were observed for two years, from January 1991 to December 1992. The major findings of this study are as follows : 1) Among the 85 patients, 62.4% were between 11 and 39 years of age. Male patients outnumbered females by 1.6 : 1. 2) The most frequent complaints were nasal obstruction(86%), olfactory disturbance(69.9%) and rhinorrhea(67.7%). 3) Fifteen percent of the patients had the past history of nasal polypectomy. 4) Multiple nasal polyps(55.2%) were more frequent than single nasal polyp. 5) Bilateral nasal polyps were more frequent than unilateral polyps by 1.4 : 1. 6) Among the patients with nasal septal deviation, single polyps were found more frequently on the concave side than convex side. 7) Common sites of nasal polyps were ethmoid sinus, middle meatus and middle turbinate in its declining order. 8) Ninety-five percent of the patients had chronic paranasal sinusitis, 31.8% had nasal septal deviation, and 15.3% had chronic hypertrophic rhinitis. 9) The histopathologic types were grandular-cystic type(50.6%), edematous type(35.8%), and fibrous type(14.1%). 10) Twenty-five percent of the polyps had esosinophil infiltration and most frequent eosinophil infiltration was observed in edematous type.