The prevalence of asthma in patients suffering from food allergy or food intolerance had been studied in 1339 subjects. Of them, 165 patients (12.8%) were affected by asthma. However only 77 (5.7%) had positive prick tests for food antigens and 52 of these have a significant benefit when a suitable oligoallergenic diet was introduced. 35 out of patients were positively tested with a double-blind food challenge. The most frequent food antigen involved were milk and its derivatives and cereals, but some importance have also the additives to the food. In conclusion, in our patients suffering from food allergy or food intolerance asthma was present in 12.8% of the cases, but in only 77 (5.7%) the symptoms might be due to diet. When tested with oligoallergenic diet or with food challenge the percentage of positivity fall to 3.9% and 2.6% respectively.