Bronchial asthma often starts in early childhood. Clinical manifestation of the disease is likely due to inflammatory processes in the airways initiated by various stimuli. Developed remodelling is regularly observed in the bronchial mucosa of adult asthmatics but we still lack information about its onset and latter development with the natural course of the disease. In this study, we analysed histological findings in bronchial biopsies obtained from very young children (under 4 yr of age). We hypothesized that initial undetectable changes in the airway epithelium of children predisposed to asthma may be one of the first mechanisms leading to morphological changes in the bronchial mucosa.