Eleven patients with allergic rhinitis were studied. All subjects were sensitive to house dust mite documented by skin test, RAST score, and nasal provocation test. The patients needed lower turbinectomy because of chronic hypertrophic rhinitis. Tissues of the lower turbinate were obtained at the time of surgery, fragmented, and subsequently challenged with house dust mite in vitro. Diffusates were collected for measurement of neutrophil chemotactic activity (NCA) and histamine. NCA and histamine were released in a dose-dependent manner, and the time course of release of these mediators was identical. Release of NCA and histamine correlated significantly (p less than 0.001). The prior administration of the antiallergic drugs, disodium cromoglycate or tranilast, significantly blocked the release of NCA and histamine from antigen-challenged tissues. NCA released from nasal tissues eluted as a single peak with estimated molecular size of between 669 kd and 440 kd in three subjects and as two or three peaks in two patients. These results provide evidence that NCA might be involved in the pathogenesis of allergic rhinitis.