Due to the apparent widespread use of aerosol therapy in neonates, we surveyed the current use of aerosol therapy in Level III Neonatal Units in the USA. The indications, the methods of delivery, and the medications aerosolized were assessed. 190 of 287 (66%) NICUs responded to the survey. 186/190 (98%) NICUs indicated they use aerosol therapy. Clinical reasons for using aerosol therapy include bronchospasm (98%); antiinflammation (68%); diuresis (8%); antibiotic administration (17%); mucolysis (4%); pulmonary toilet (3%); hemostasis in pulmonary hemorrhage (2%). For intubated neonates, 84% of respondents utilize nebulization (neb), 16% use metered dose inhalers (MDI). For nonintubated infants, 95% of respondents use neb, 5% use MDI. With respect to medications aerosolized in NICU patients, all 186 NICUs that practice aerosol therapy use beta adrenergic agents; 59% use Na cromoglycate; 44% corticosteroids; 9% diuretics; 20% ipratropium; 9% racemic epinephrine; 4% mucomyst. 12% indicated use of aminoglycosides. 3 NICUs indicated use of either cocaine or epinephrine for hemostasis in pulmonary hemorrhage. Of survey responders who use corticosteroids, 50% nebulize steroids despite existing evidence that the respirable particle size for steroids is more effectively achieved by MDI. Conclusion: Despite a paucity of data on aerosol drug delivery, clinical efficacy, and safety, the majority of NICUs responding to the survey do use aerosol therapy. Given the widespread use, varying clinical indications, methods of delivery, and types of drugs it is critical to document optimal dosing, delivery, safety, and efficacy.