Childhood asthma is a heterogeneous inflammatory disease with several wheezing phenotypes (transient, atopic, nonatopic, and obese) and various clinical expressions of multifactorial origin. All forms, however, follow a similar course characterized by recurrent episodes of airway obstruction. Studies have shown that the onset of disease occurs early in life for the great majority of asthmatics, that airway inflammation and remodeling are present in schoolchildren with asthma, and that even infants with persistent wheezing present airway inflammation. The difficulty lies in the early identification of infants with recurrent wheezing who are at risk of suffering persistent asthma later in life. The Asthma Predictive Index, a simple tool validated in a longitudinal study, has been suggested for early identification of infants with recurrent wheezing who are at risk of developing asthma and whose lung function has undergone major irreversible damage during the first years of life.