A postal questionnaire, completed by parents, was used to study the prevalence of respiratory symptoms in 250 children with atopic dermatitis who had attended pediatric dermatology clinics in London within the past 5 years. A response rate of 84% was achieved. Each child had a control matched for age and sex, whose parents filled in an identical questionnaire. The prevalence of wheezing was 76% in the atopic dermatitis group and 12% in the control group. Of the children with atopic dermatitis who wheezed, 87% had been given a diagnosis of asthma by a doctor, compared with 40% of the control children who wheezed. Overall, 68% of the children with atopic dermatitis had been given a diagnosis of asthma by a doctor. This prevalence of respiratory symptoms and of diagnosed asthma is substantially higher than has been shown in previous studies. As the test population consisted of children who had been referred to a tertiary center for management of their skin disease, this higher prevalence may partially reflect the increased severity of atopic dermatitis in the study group, as well as the heightened awareness of the association between these two diseases by their parents and physicians.