Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are the 2 forms of desensitization for allergic diseases which are used internationally. Despite the lack of sufficient evidence of the mechanism, SCIT has been used in Japan. When SCIT is performed appropriately, it is effective for allergic rhinitis, as supported by high-level evidence, including the results of meta-analysis. However, its use in Japan has not become widespread due to various problems, including the risk of anaphylaxis. Therefore, attention is being focused on SLIT because it is easier to perform but may be similarly effective and has been extensively discussed and evaluated internationally. Comparison of SCIT and SLIT can only be done with some allergen, which has also been discussed extenesively. Many patients and physicians would welcome the use of SLIT in Japan, and its first use against pollinosis due to Japanese cedar pollen is planned for 2014.