Few large studies concerning the importance of food allergy in adolescents and adult patients with atopic dermatitis exist. The evaluation of food allergy to egg white and yolk, peanuts, soy, cow milk and wheat in patients suffering from atopic dermatitis. Two hundred forty patients (70 men, 170 women) were examined. Complete dermatological and allergological examination was performed in all patients, including specific IgE, skin prick test and atopy patch test. The challenge test was performed according to the results of examinations with suspected foods. The food allergy to peanuts was confirmed in 20% of patients, to egg in 6%, to soy in 3.3%, to wheat in 2.5% and to milk in 0.8% -altogether in 65 patients (27.5%). The positive results in examinations without clinical symptoms of food allergy were recorded in another 78 patients (32.5%). The diagnostic work-up should comprise not only the laboratory methods, but also the diagnostic hypoallergenic diet and the challenge test.