Background: Food allergy is a worldwide serious public health issue. The aim of this study was to determine the most frequent food allergen causing IgE-mediated hypersensitivity reactions in Lebanese patients of different ages. Methods: 1182 patients showing symptoms of food allergy were screened for specific IgE antibodies to 35 food allergens using Euro Immun immune blot assay test. Results: The major cause of hypersensitivity in 1 to 10 years old patients was Cows’ Milk where it was: Soybean in 11 to 20 years old patients; Beef in 21 to 30 years old patients; Potato in 31 to 40 years old patients; and Shell fish mix in patients more than 40 years old. Further, a significant correlation between presence/absence of specific IgE and total serum IgE levels was absent. Conclusion: We define the most common food allergens between different age groups of Lebanese patients which is significant for public health in Lebanon.