Inverted papilloma is a benign epithelial tumor but has somewhat malignant behavior. In spite of its rarity, the interest of inverted papilloma has been increased by high rate of recurrence, invasion into adjacent structure and associated malignancy. Clinical presentation, surgical treatment and histopathological findings of associated malignancy were reviewed from 1986 to 1992 in 14 cases of inverted papilloma. Lateral rhinotomy(10 cases) and midfacial degloving approach(4 cases) have shown fairly good result during adequate follow-up. In this series of 14 patients 10 showed no evidence of dysplasia or malignancy while 14 had an associated invasive squamous cell carcinoma. In 2 of 4 associated malignancies showed the gradation of epithelial change ranging from benign inverted papilloma to dysplasia, to carcinoma in situ and to invasive squamous cell carcinoma. 2 of 4 associated malignancies arised in inverted papilloma which have recurred following repeated surgery. From these observation it would seem that squamous cell carcinoma arises from the inverted papilloma.