Eosinophils play an important role in the development of bronchial asthma, and the association between ICAM-1 and activation and migration of local eosinophils is attracting attention. Using an asthmatic model of dual phase bronchial response, the effects of anti-ICAM-1 antibody on the airway resistance, cell composition in the bronchoalveolar lavage fluid (BALF) and ultrastructure of bronchial ciliated epithelium were examined under the provoked response by inhalation of the antigen. By administration of anti-ICAM-1 antibody, the late asthmatic response (LAR) was suppressed. In the examination of bronchoalveolar lavage fluid, a significant decrease in eosinophils was found in LAR. In examining transmission and scanning electron microscopies, no difference was found in the immediate asthmatic response, but marked suppression of deciduation of bronchial ciliated epithelium was observed in LAR. These results indicated that anti-ICAM-1 antibody suppressed bronchial asthmatic attack, mainly in LAR, by controlling differentiation and migration of eosinophils.