The incidence of food allergy has been evaluated in 67 asthmatic patients (allergic asthma: 52, intrinsic asthma: 15). History was positive for post-meals attacks (7), symptoms involving other target organs (61%). Prick tests were found positive in 17/60; intradermal 77/682. Out of 110 human basophil degranulation tests or RAST, performed in 44 patients, 21/15 patients were found positive. Out of 18 inhalation challenges, 7 were positive. Out of 17 food oral challenges, 6 were positive (8 patients). A definite diagnosis of food allergy was accepted for 9 patients. Elimination diet, with 600 mg/day of cromolyn, induced a major improvement in 7 patients within 3 months, with 2 further failures after 1 year. A successful elimination diet was correlated with a positive food challenge. The relative incidence of food allergy in asthmatic adults is discussed (5.8%), as well as a non-immunologic mediated intolerance to food additives in intrinsic asthmatics, the incidence of vegetable allergies in pollen-sensitive patients, the procedures and meaning of inhalation and oral challenges, the relative importance of trophallergens. Food allergy appears to be a variable co-factor in bronchial hyperreactivity.