Guinea pigs were exposed to an aerosol of grifolan (300 µg/m³) 4 hours daily for five weeks. A lung lavage was performed and the number of inflammatory cells counted. Histological sections were prepared from the lung and the trachea. There was a higher number of eosinophils in the lung lavage from exposed animals as compared to controls (1.6(0.8) million cells/lung vs 0.8(0.6), p<0.01). In the airway epithelium, the number of eosinophils was also larger (68.6(13.6) vs 36.8(10.6), p<0.001). There was no increase in the number of neutrophils in the lavage. The results further support earlier findings that (1->3)-ß-D-glucan causes an inflammatory response in the airways which is different to the marked neutrophilia caused by endotoxin.