Inverted papillomas of the nose and paranasal sinuses are found to be associated with squamous cell carcinomas in a small percentage of cases. In June 1993, we had an unusual experience in an old male who presented with the symptoms of epistaxis and a palpale mass over the right cheek for 6 months. CT and MRI revealed an expansive mass completely filling the right maxillary sinus with mild destruction of the lateral posterior wall and anterior wall. The patient then received subtotal maxillectomy and ethmoidectomy. The histopathological diagnosis was proved as squamous cell carcinoma arising from inverted squamous papilloma. The terminology, clinical presentation, treatment and outcome of inverted papillomas and squamous cell carcinomas in association with inverted papillomas were discussed.