It is widely recognized that the incidence of allergies and allergic diseases is on the rise globally. As an international umbrella organization for regional and national allergy and clinical immunology societies, the World Allergy Organization is at the forefront of a combined united effort across nations and organizations to address this global concern by promoting the science of allergy and clinical immunology, and advancing exchange of information.The World Allergy Organization's State of World Allergy Reports will provide a biennial review of allergic diseases worldwide, consider their medical and socioeconomic contexts, and propose effective approaches to addressing these problems.In this first State of World Allergy Report 2008, experts from different regions of the world have attempted to define the extent of the global allergy problem, examine recent trends, and provide a framework for the collaboration among world medicine, science, and government agencies that is needed to address the rapidly developing issues associated with allergy and allergic diseases.