The continuously increasing amount of children presenting with allergic symptoms and the early age at which the symptoms occur are the factors which influence researchers to seek the reason for this. Genetic and environmental factors play a great role in the development of allergic diseases. Quantitative and qualitative changes in the genotype which affect the phenotype occur very slowly therefore it is more likely that the environmental changes are responsible for the multiplication of allergy diagnosis in children. The environmental factors which were analyzed, if they can induce the development of allergic diseases are  indoor and outdoor allergens, environmental contamination, stress, diet, infections, housing conditions in which the exposition to specific chemical factors is present and medication used by pregnant or lactating woman and/or the child. Allergic diseases  appear more often in the population of developed countries comparing to developing countries and also more often in rich comparing to poor societies. This seems to be caused by different exposition to allergens and a different life style. Numerous studies regarding factors which influence the development of allergic diseases are still being performed. In this article we present some conclusions from the current research.