BACKGROUND We have shown the beneficial effects of N-acetylcysteine (NAC) on posttransplant lung function, when both donor and recipient were pretreated intravenously. However, systemic treatment of multiorgan donors may not be clinically relevant. Thus, we hypothesized that ex vivo treatment of donors with nebulized NAC would be adequate to prevent from ischemia-reperfusion injury after lung transplantation. METHODS Lungs were retrieved from domestic pigs and stored at 4°C for 24 h followed by 2 h of ex vivo lung perfusion (EVLP) to administer 50 mg/kg of NAC via nebulization in the NAC group (n = 6). The control group received nebulized saline (n = 5). Left lungs were transplanted and isolated at 1 h of reperfusion by occluding the right main bronchus and pulmonary artery, followed by 5 h of observation. Physiological data during EVLP and after reperfusion were recorded. Inflammatory response, markers of oxidative stress, and microscopic lung injury were analyzed. RESULTS There was a trend toward better oxygenation throughout reperfusion period in the treatment group, which was accompanied by inhibited inflammatory response related to reduction in myeloperoxidase activity during EVLP and nuclear factor-κB activation at the end of reperfusion. CONCLUSIONS Ex vivo treatment of donor lungs with inhaled NAC reduced inflammatory response via its antioxidant activity in experimental porcine lung transplantation.