Objective evidence of food hypersensitivity was sought by the use of exclusion diets and provocation tests in 23 patients who attributed a wide variety of symptoms to food allergy. Hypersensitivity to ingested substances was confirmed in 4, each of whom presented with typical atopic symptoms. None of these had psychological symptoms, but a high incidence of psychiatric disorder was found in patients whose belief that they had a food allergy could not be confirmed.