The clinical, diagnostic, and therapeutic features of 257 papillomas of the ear, nose and throat were studied. These tumors were found in a population of about 500,000 inhabitants over a 20-year period (1973-1992). The clinical manifestations of papillomas were varied and more dependent on location than on the size or number of lesions. The most frequent symptom was a foreign body sensation. Twenty-four percent of cases were asymptomatic and the diagnosis was made during a general physical examination; such diagnoses were most frequent in the pharynx. The mean duration of symptoms before visiting a physician was 10 months (longer in papilloma of the oral cavity and shorter in the pharynx). The initial clinical diagnosis was correct in 63% of cases. Lesions of the oral cavity presented most diagnostic problems and those of the pharynx the least. A clinical diagnosis of cancer was made most often in the larynx. Treatment was surgical in every case. Twenty percent required more than one operation to remove the papilloma.