The death rate among patients with asthma in Japan has been reported by Japan's Ministry of Health and Welfare to approximately 5/100,000 population. Over the past 15 years, this rate has remained relatively constant, but it is higher than that in western countries. To clarify recent trends in adult asthma mortality, the Japan Asthma Death Investigation Committee studied the clinical characteristics of 649 patients who died of asthma between 1986 and 1991. The annual number of deaths decreased slightly: from 145 in 1986 to 89 in 1991. There was a large difference between sexes: the male:female ratio was 3:2. Most patients ranged in age from 50 to 70 years old. It is noteworthy that in one third of the patients death was caused by asphyxic-type asthma, while status asthmaticus was the cause in only 23.7%. The number of patients with mild or moderate asthma was slightly increased, although patients with severe asthma accounted for at least 70% of all deaths. The main causes of fatal asthma attacks were airway infections, fatigue, and stress. Other responses on the questionnaires indicated the following areas of concern: deficiencies in patient education, delays in treatment with corticosteroids and other antiasthma drugs, and delays in provision of emergency treatment.