Allergic disease is a complex disorder in which the interaction between environmental and genetic effects may modify both the susceptibility to and severity of the disease. Over the last few years, our understanding of the genetic basis of allergic diseases has improved markedly, which has led to the identification of several chromosome regions and loci showing linkage to allergic disease. As another approach, association studies between candidate gene polymorphisms and allergic diseases have been conducted in many areas and replicated in different ethnic groups. These approaches need to be followed by validation processes to confirm their functional relevance in the pathophysiology of allergic disease. This review updates genetic studies of and recent findings in, allergic disease.