Although rabbits are common domestic pets, severe respiratory allergic reactions to rabbits in households are unusual. Ory c 1, a 17-kDa glycoprotein found in saliva and fur, has previously been identified as a major rabbit allergen. In this report, we describe the cases of three patients with rabbit allergy who presented with asthma and/or rhinitis while living in households with detectable levels of serum-specific IgE and major IgE binding components. Three patients with rabbit allergy and 18 unexposed nonatopic healthy controls were enrolled. Enzyme-linked immunosorbent assays (ELISA) for serum-specific IgE and IgG(4) to rabbit epithelium and inhibition ELISA were performed followed by sodium dodecye sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE immunoblotting. All three patients with rabbit allergy had high serum-specific IgE antibody levels compared with controls. The results of the inhibition ELISA showed significant inhibition with the addition of rabbit epithelium, whereas no significant inhibition was noted with the addition of cat and dog epithelia. Two IgE-binding components with molecular weights of 16 kDa and 67.5 kDa were identified by IgE immunoblotting. In conclusion, rabbit exposure may induce IgE-mediated bronchial asthma and/or rhinitis in domestic settings.