An objective of this article is a review of contemporary knowledge on various environmental factors, that influence prevalence and course of allergic diseases, like asthma, allergic rhinitis, atopic dermatitis and also contact dermatitis. Surrounding climate may directly influence each patient, but also determines type of flora and fauna within particular geographical regions and thus affects sources of airborne and food allergens. Epidemiological studies suggest that there is a strong relationship between air pollution and development and exacerbation of asthma and other allergic diseases--main attention has been concentrated on gaseous materials such as ozone (O(3)) and nitrogen dioxide (NO(2)), as well as particulate matter (PM), generated by car traffic and industry. Diesel exhaust particulate (DEP) has the ability to bind proteins and may serve as a potential carrier of allergens, penetrating deep into respiratory tract. Among the most extensively studied environmental factors influencing allergy are airborne allergens: dust mites, pollens, fungi and animal dander. Foods may elicit both true IgE-mediated allergy and also various non-immunological reactions, associated with direct release of mediators or toxic activity. It has been estimated, that over 85,000 chemicals are recognized in the human environment and they may act as contact allergens or irritants, causing allergic or non-allergic contact dermatitis. Among them metals, fragrances, preservatives, botanicals and paraphenylenediamine are considered as the most significant. Infections have always been associated with etiopathogenesis of allergic diseases and they may contribute to exacerbation of their course.