Several unfavourable trends and epidemics of fatal asthma have been registered in various developed countries of Europe, the United States and New Zealand over the last three decades. These have been related to problems in the treatment of the disease, following the introduction and/or inappropriate utilization of selected beta-agonist treatments. Thus, trends in mortality rates from bronchial asthma have been analyzed in Switzerland, where the Eighth Revision of the International Classification of Diseases has been in operation from 1969 to 1993. Overall age-standardized mortality rates (world standard) declined, from 4.3/100,000 males in 1969-73 to 2.8 in 1989-93, and from 2.0 to 1.5/100,000 females. The declines were consistent in both sexes for the age group 35 to 64 years, and some downward trend was observed also above age 65, particularly in males. Asthma mortality trends were inconsistent in children and young adults ( < 35 years), with some increase in males aged 15 to 34 after 1983, in the absence however of any significant linear trend in rates. Thus, trends in asthma mortality in Switzerland showed a moderate and steady decline in rates, particularly in middle aged males, in the absence of any systematic upward trend or epidemic peak. Still, the trends were only moderately favourable, and in the early 1990's about 250 deaths per year were attributed in Switzerland to bronchial asthma, i.e. an avoidable, in principle, cause of death.