This study describes the natural history of atopic and wheezy disorders from birth to adult life in a cohort at risk of atopy. One hundred subjects born in Poole, England, were selected at birth in 1976 on the basis that at least one parent was atopic. Subjects were examined annually in the preschool years, and at the ages of 11 and 22 yr. Skin prick tests and total serum immunoglobulin E (IgE) were performed at each visit, and at 11 and 22 yr, bronchial hyperresponsiveness (BHR) to inhaled histamine was measured. Sixty-three subjects remained on follow-up at 22 yr. The annual prevalence of both wheeze and atopy increased with age. Twenty-five percent of adults showed both wheeze and BHR (asthma). Remission of wheeze was common in subjects younger than 5 yr of age and likely if wheezing occurred on less than two occasions, but wheeze at 11 yr was likely to persist. Sixty percent of the adult subjects with asthma developed sensitivity to common allergens by the age of 2 yr and were showing BHR by mid-childhood. Sensitization to dietary allergens occurred in infancy and waned after early childhood but predicted the early sensitization to inhalant allergens. In conclusion, adults with asthma can begin wheezing at any age but tend to sensitize early and have abnormal airway characteristics by the age of 11 yr.