There have been few reported cases of occupational asthma induced by Pinellia ternata (Banha), and the mechanism responsible for this type of asthma is still undetermined. We report a case of Banha-induced occupational asthma with IgE-mediated mechanism. The patient had positive skin responses to Banha extract and Banha-specific bronchial challenge elicited an early asthmatic response. The serum-specific IgE binding to Banha extract was detectable and completely inhibited with the additions of 0.1 µg/mL of Banha extract on ELISA inhibition. Seven IgE binding components to Banha extract (6.5, 22, 24, 32, 34, and 48 kDa) were detected using SDS–PAGE and immunoblot analysis. In conclusion, the results of this study suggest that P. ternata (Banha)-derived allergens are able to cause IgE-mediated bronchoconstriction in exposed workers.