A solid-phase immunoenzymatic technique for the detection of allergen-specific IgE antibodies in serum is described. The binding of such antibodies to allergen insolubilized on cyanogen bromide-activated paper discs was detected by a subsequent two-step procedure involving the use of rabbit antihuman IgE and goat antirabbit IgG coupled with peroxidase. A solution of 3-3' diaminobenzidine and hydrogen peroxide, employed as the color indicator system, turned the discs dark brown in positive cases. Discs carrying 11 different inhalant allergens were tested with sera containing allergen-specific IgE antibodies. Agreement between the results of this technique and the RAST was seen in 85% of 310 tests performed. In the clinical practice of otorhinolaryngologic allergy, this test may prove to be an important laboratory adjunct to clinical history and diagnostic skin test in the identification of the incriminated inhalant allergens.