Bronchial asthma is an inflammatory disease. The characteristic pathological features of epithelial cell loss, goblet cell hyperplasia, increased deposition of collagen beneath the basement membrane, mast cell degranulation, and inflammatory cell infiltration of the mucosa are not limited to fatal asthma. Similar inflammatory events have been observed in subjects who would be considered to have clinically stable asthma. These observations would suggest that pharmacological treatment directed against the underlying inflammatory processes in asthma should not be limited to those patients with severe forms of the disease.