Eosinophilic nonallergic rhinitis is one of the major forms of nonallergic rhinitis. It is characterized by the presence of many eosinophils in nasal secretions, a negative history for allergen exacerbation, and negative skin tests. It is often associated with nasal polyps and shares their exquisite sensitivity to corticosteroid therapy, both systemic with prednisone or topical with flunisolide. Patients with rhinitis can be separated into diagnostic categories and assigned scores on the basis of history of allergic reactions, status of nasal mucosa, response to skin tests, and IgE titer. Based on these criteria, in a study of 142 patients with rhinitis, those with allergic or probable allergic rhinitis could clearly be separated from those with nonallergic rhinitis. Thirty-four percent had allergic rhinitis (mean score 5.4), 15% had probable allergic rhinitis (mean score 3.8), 37% had vasomotor rhinitis (noneosinophilic, nonallergic rhinitis; mean score 0.75), and 15% had eosinophilic nonallergic rhinitis (mean score 0.71). Eighty-three percent of patients with eosinophilic nonallergic rhinitis responded to antihistamines and 93% responded to the topical corticosteroid flunisolide, making the total response 90%. The response of the latter patients to these medications was statistically better than the response of those patients with allergic rhinitis.