Background: Food allergy diagnosis is performed by a double blind placebo controlled challenge; however, in a lot of patients, it is only based on clinical history, skin prick tests, or parents’ perception. There is a high frequency of elimination diets without an adequate approach. Objective: To analyze the results of diagnostic tests in a group of children with elimination diet-based on suspected food allergy and verify such studies with double blind placebo-controlled test challenge. Material and method: An observational, analytical and prospective study was done in a group of patients with elimination diet for suspected food allergy. We performed prick test, Prick-to-Prick test and patch test and the positive ones were verified by double-blind placebo-controlled challenge. Results: Fourty-three patients were included within a total of 1,935 tests. Both approach for immediate and late sensitivity had not statistically significant relationship between a positive test and the elimination of food. Until now, we had 4 (8%) positive challenges out of 50. Conclusion: The frequency of allergy proved by double-blind placebo-controlled test in 50 challenges was of 8% (4/50), thus, in the preliminary report we found a high frequency of elimination diets without adequate support. It is very important that food allergy diagnosis is accurate and based on an appropriate approach; since the implementation of an elimination diet in pediatric population can have a negative influence on their growth and development.