Wheezy bronchitis in infancy and early childhood are important problem in pediatric practice. Wheezing can be manifestation of different diseases, including asthma which is one of the most common. Retrospective analysis and long term prospective studies proved that asthma diagnosis is justified even in small children. In this age group asthma diagnosis relies mainly on clinical criteria (Asthma Predictive Index) and exclusion of other causes of wheezing. Positive response to therapeutic trial with anti-inflammatory drug and bronchodilator confirms asthma diagnosis.