Lung function and bronchial response to methacholine were studied in 47 young adults who had had childhood asthma, and after a period of 14-21 years, showed a different clinical evolution. At present, these subjects have been classified in four clinical groups: asymptomatic, rhinitic, asthmatic only due to exercise, and asthmatic. The same study was performed in 23 healthy individuals without personal histories of respiratory or allergic pathology. We found low spirometric basal values in both the asthmatic group (FEV1 and FEF25-75) and in the group with asthmatic responses to exercise (FEF25-75). No significant differences were found among asymptomatic, rhinitic, and control groups. While airway hyperreactivity was observed in patients who still had asthma, the bronchial response to methacholine in asymptomatic and rhinitic groups was not different from the control group. We conclude that both lung function and bronchial response to methacholine in most of the adults who had asthma in infancy and had been without asthmatic symptoms for many years are similar to those observed in the general population.