Concern about the rising asthma mortality and morbidity in several countries in the 1980s, and the consequent development of international guidelines for diagnosis and management of asthma, gave reason to evaluate national mortality and hospital admission data from the Netherlands for asthma [International Classification of Diseases (ICD) 493] over the period 1980-94, as well as for chronic obstructive pulmonary disease (COPD) (ICD 490-2, 496) and acute bronchi(oli)tis (ICD 466), according to age (0-4, 5-34, 35-64 and > or = 65 years). Rates per million population per year were calculated and time trend analyses were performed. Hospital admissions for asthma showed a decrease in all age groups except in age group 0-4 years. In this age group, an increase was found which continued in the 1990s. Hospital admissions also increased for COPD and acute bronchi(oli)tis in the age group 0-4 years. These increases, however, had no impact on the respiratory mortality, which remained stable and even fell for acute bronchi(oli)tis. Asthma mortality showed a large decline in the 1990s in age group > or = 65 years in both sexes, and also fell, to a lesser extent, in age group 35-64 years. In both age groups, rising COPD trends were found in hospital admissions and mortality, except in males aged 35-64 years, in whom trends fell in the last decade. In age group 5-34 years, asthma mortality declined over the whole study period, whilst the other respiratory trends were stable. It is concluded that asthma statistics in the Netherlands indicate favourable development, except for the age group 0-4 years. In this age group, morbidity from asthma and from other reactive airway disorders is still of great concern.