Tissue samples from the polypous mucous membrane and the inferior nasal concha were taken from 13 patients with polyposis nasi and from 12 other patients with an additional intolerance to analgesics. The tissue of the inferior nasal concha from patients without polyposis nasi served as a control. The relative histamine content of the samples (in ng/mg dry weight) and the relative histamine release (in %) after addition of acetylsalicylic acid (ASA) were determined. A significantly higher relative histamine content in the tissue samples of polyp patients without an intolerance to analgesics was seen in comparison to the other two groups. The relative histamine release of both patient groups with nasal polyposis was comparable. The control group exhibited both an increased spontaneous release of histamine as well as a higher relative histamine release from the tissue of the inferior nasal concha.