In 1989 a survey of 543 New Zealand rural adolescents of largely Maori descent was undertaken to determine the prevalence of asthma symptoms, bronchial hyperresponsiveness (BHR) and atopy. The overall prevalence of asthma was estimated at 13.7%, BHR at 13.4% and atopy at 31.1%. These rates were similar across the age range 13 to 18 years. The prevalence of BHR among those without asthma symptoms was 3%. Both current asthma symptoms and BHR were more common among females, but there was no difference between the sexes in the proportion with atopy. The prevalence of asthma symptoms was higher among Maoris than nonMaoris, but this difference disappeared when allowance was made for current smoking. There was a similar prevalence of BHR and atopy between these two ethnic groups. There was a similar prevalence of asthma but lower prevalence of BHR than was reported among 7-10 year olds in an urban Auckland survey. The low prevalence of BHR among those without asthma symptoms, and the uniform frequency of asthma symptoms, BHR and atopy over the age range suggest that adolescents would be a particularly useful population for national or international comparisons of the prevalence of asthma, BHR and atopy.