Summary: Drug deposition in the respiratory system is a key element determining the effectiveness of inhalation therapy. The amount of budesonide deposition administered by nebulization may be influenced by the nebulization method used (e.g. type of nebulizer, use of valved-holding chamber), inhalation technique (e.g. body position, breathing pattern) and budesonide preparation (e.g. size of budesonide crystals, viscosity). This article discusses the above issues in detail and presents them graphically for better understanding.