Administration of drugs via the inhalation route will find new indications in the therapy for lung diseases. Furthermore, aerosolised drugs are of increasing interest for systemic treatment. The inhalation of antibiotics is already a well established therapy in cystic fibrosis. In bronchiectasis, severe COPD with bacterial airway colonisation and in mechanically ventilated patients, aerosolised aminoglycosides may provide benefit. Substitution of alpha1-antitrypsin in lung emphysema via inhalation seems to be superior to the intravenous administration. Inhaled insulin has currently been withdrawn from the market in spite of being approved by FDA and EMEA. However, intensive scientific research is still ongoing and many clinical studies are underway in the field of the inhalation of insulin, heparins and other systemic treatments.