Repair is an integral part of every inflammation. Injured cells are replaced by new cells of the same type or by connective tissue. This may result in restitution "ad integrum" or lead to structural changes referred to as remodelling. For many years the importance of this phenomenon for the course of asthma, an undoubtedly chronic inflammatory disease, was underestimated. The presence of only partial reversibility of airflow obstruction in some patients with asthma has significantly changed our view on that problem. The irreversible component of airway obstruction is more prominent in patients with severe disease and persists despite aggressive anti-inflammatory treatment. Recent studies have proved that remodelling in asthma encompasses not only the bronchial tree, but also alveolar tissue. There are many factors supposedly responsible for lung reconstruction characteristic of asthma: mediators, cytokines, and growth factors. Better understanding of these processes should provide a basis for novel, long-term therapeutic strategies in asthma.