The prevalence of asthma in children has increased substantially in many countries in recent decades, but it is not clear how much this trend has continued into the 1990s. This study aimed to estimate the current prevalence of asthma and wheeze in British primary schoolchildren and to determine whether there has been any increase in the prevalence of these conditions since 1988. The prevalence of self-reported wheeze and asthma was measured by parental questionnaire in 22,968 children aged 4-11 yrs attending primary schools in the Nottingham area of England in 1995, and these estimates were compared with data from a subsample of the same schools in 1988. In 1995, wheezing ever was reported in 24.0% of children, wheezing in the past year in 15.1% and diagnosed asthma symptomatic in the past year in 8.8%. All measures have increased in prevalence since 1988, in absolute terms by 7.7% for wheeze ever, by 2.6% for wheeze in the past year and by 2.7% for asthma. The increases were greater in females than males, but did not vary with age. In conclusion, the prevalence of asthma has continued to rise in British schoolchildren since the late 1980s, particularly in females, and across all ages.