The incidence of food allergy is increasing especially during the last few years. This phenomenon coincides with the changes in the eating habits and in the environment. The immunopathology of food allergy is complex. However most food allergies are IgE-mediated immunological reactions to specific foods. This paper discusses generally the current knowledge of food allergy, especially: basic definitions, mechanism of food allergy, food allergens/antigens, cross-allergenicity and common methods used to produce of hypoallergenic foods.