Supplement Issue: International Archives of Allergy and Immunology 2000, Vol. 121, Suppl. 1 Since 1993, several guidelines for the diagnosis and treatment of asthma have been published in Japan. A recent survey of institutions specializing in asthma treatment in Japan has shown that care of asthma patients has improved significantly. Fewer patients require emergency treatment or hospital admissions. However, that asthma remains a serious health problem is indicated by the fact that the number of diagnosed cases continues to rise. The death toll remains constant. The newest standards include a definition of asthma, a discussion of risk factors, a classification of levels of severity, plus information on patient education, diagnosis, and pharmacological control of the condition. New to the standards are sections dealing with epidemiology, etiology, pathophysiology, prevention, as well as quality of life issues. The treatment of both adults and children is considered. The English version is intended to provide information on the treatment of asthma in Japan with the aim of contributing to the prevention and treatment of asthma world-wide.