Acute Respiratory Distress Syndrome (ARDS) is a major medical emergency requesting acute therapeutic intervention. Here we report that Nitric Oxide (NO) gas attenuates ARDS in mice. Using a novel portable NO generator we found that NO at 20 ppm attenuates endotoxin (LPS) induced neutrophil recruitment lung alveolar epithelial damage reduced inflammatory cytokines, neutrophil. Therefore, the data suggest that the use of a portable NO generator may be considered as an interesting therapeutic possibility for patients with severe ARDS.