A series of 95 consecutive patients who have had a polypectomy was investigated with regard to clinical history and the morphology of the polyps. The results were compared with a series of 203 patients with allergy, of whom 12 had been polypectomized. The study revealed that a high percentage of the 95 patients had subjective complaints, particularly nasal congestion, nasal discharge, sneezing, headache, snoring and a loss of smell. The latter was present in nearly 58 % of the patients, and persisted long after the operation in a third of the cases. More than 50 % of the 95 patients had had 3 or more polypectomies. Rather few patients suffered from allergy-like conditions. Eighty-two of the 95 polyps were of the ordinary, oedematous, eosinophilic type; 7 were neutrophilic, fibro-inflammatory; 5 showed pronounced hyperplasia of the seromucinous glands, and 1 was a so-called polyp with atypical stroma. Only 6 % of the 203 patients with allergy had had a polypectomy. Ten of the 12 polyps removed from the series of patients with allergy were of the ordinary type and 2 of the fibro-inflammatory type. A review of the literature is done concerning the association between nasal polyp and different diseases. The results of the present study support the concept that allergy is not the only cause for nasal polyps and that the accumulation of eosinophilic granulocytes observed in most polyps is often not related to allergy.