Inverted papillomas (IPs) in the nose or the paranasal sinuses exhibit a tendency for rapid growth with bone destruction, a high recurrence rate, and an association with malignancy, requiring early diagnosis and aggressive surgical therapy. A number of operative approaches have been reported in the literature, with greatly varying results. Furthermore, the incidence of IP and the association with carcinoma are not well-established. In this study, we present a series of 42 patients with IP. Drawing from the resources of two institutes of pathology, we reviewed all specimens of nasal cavity or paranasal sinus tissue taken between the years 1975 and 1986, and performed a thorough follow-up of all IP patients. The incidence was found to be 0.6 cases per 100,000 inhabitants per year in a well-defined representative geographic region. Two patients had concomitant carcinoma. When the initial surgical approach was lateral rhinotomy, the recurrence rate was 50%. This was not significantly different from that noted following excision through a sinusectomy (62%) or simple endonasal excision (43%). However, initial procedures were selected individually, mainly on the basis of tumor size and location. Accordingly, a limited procedure is considered justified even in cases with lateral lesions, if the tumor is sufficiently visible and confined. In other cases, lateral rhinotomy is required. Septal IPs are often detected at an early stage and are therefore often amenable to local excision.