To determine whether mortality from asthma in Japan has increased, and to examine the age-, sex-, and race-specific mortality rates from this disease and their secular trends in both Japan and the US, vital statistics from 1979 through 1988 were studied. Overall, rates were highest among Japanese and decreased from 1979 to 1988, while rates in the US were lower and increased somewhat, especially among Blacks (whose rates were intermediate, in general, between Japanese and US Whites). Age-specific rates showed the greater asthma mortality in Japan to be due to deaths at ages greater than 50 or 60 years. The downward trend in the Japanese, unlike US Blacks and Whites, was due specifically to decreasing rates among the youngest and the oldest age group between the earlier and later years of the period, 1979-1988.