Rationale: S-nitrosothiols (SNO) inhibit immune activation of the respiratory epithelium and airway SNO levels are decreased in inflammatory lung disease. Ethyl nitrite (ENO) is a gas whose chemical properties favor SNO formation. Augmentation of airway SNO by inhaled ENO treatment may decrease lung inflammation and subsequent injury by inhibiting activation of the airway epithelium. Objective: To determine the effect of inhaled ENO on airway SNO levels and LPS-induced lung inflammation/injury. Methods: Mice were treated overnight with inhaled ENO (10 ppm) or air followed immediately by exposure to aerosolized LPS or saline. Parameters of inflammation and lung injury were quantified one hour after completion of the aerosol exposure and correlated to lung airway and tissue SNO levels. Measurements and Main Results: Aerosolized LPS induced a decrease in airway and lung tissue SNO levels including S-nitrosylated NF-B. The decrease in lung SNO was associated with an increase in lung NF-B activity, cytokine/chemokine expression (KC, TNF, IL-6), airway neutrophil influx, and worsened lung compliance. Pretreatment with inhaled ENO restored airway SNO levels and reduced LPS-mediated NF-B activation thereby inhibiting the downstream inflammatory response and preserving lung compliance. Conclusion: Airway SNO serves an anti-inflammatory role in the lung. Inhaled ENO can be utilized to augment airway SNO and protect from LPS-induced acute lung injury.