A total of 139 workers (71 % of the available work force) in four grain elevator stores in Aalborg, Denmark, participated in a cross-sectional study on the prevalence of storage mite allergy among grain elevator workers. All underwent interview, prick test with a standard panel of allergens and the storage mites Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae, RAST to the three above-mentioned storage mites plus Glycyphagus domesticus and wheat, measurement of serum total IgE, and spirometry. Pulmonary symptoms were present among 44%, nasal and eye symptoms among 48%. Thirty-one per cent complained of work-related respiratory symptoms. Fourteen per cent of these workers had only nasal symptoms. Comparing the prick test result and the history, 6.4% had respiratory storage mite allergy, while 15.9% were sensitized to storage mites. Storage mites seem to be the most important allergen among grain elevator workers in Denmark. Faunistic examination of samples of grain and dust showed that storage mites, in particular A. siro, L. destructor and T. longior, were found in 73% of grain samples, while all dust samples contained mites.