This study is an investigation on whether allergy, and especially food allergy, is more common in patients with secretory otitis media (SOM) than in others. At the same time, the effectiveness of the cytotoxic leucocyte test (CLT) as an aid in the diagnosis of food allergy was also studied. The material comprised 90 patients: 69 suffering from secretory otitis media and 21 without the disease as controls. Patients were studied using allergy history, ear status, tests for nasal and blood eosinophilic cells, total IgE, skin tests for 20 allergens, RAST for milk and wheat, immunoglobulin A, G and M, precipitating antibodies for milk and gluten, Mantoux test, and the CLT for 23 allergens. Allergy was found in 20% of the SOM patients and 10% of the control patients; the difference was not statistically significant. The best methods for verifying allergy were history, skin tests, and tests for nasal eosinophilic cells. Laborartory tests could not verify objectively that food allergy was more common among SOM patients than controls, although 16% of the SOM patients compared with none of the controls had a history of food allergy. Of the tests used, the CLT correlated best with a history of allergy, but the results of the different tests were not in accordance with each other.