Antrodia camphorata (AC) has been used as a herbal medicine for drug intoxication for the treatment of inflammation syndromes and liver-related diseases in Taiwan. This study demonstrates the protective effect of the methanol extract of AC (MAC) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Mice were treated with MAC 1 h before the intratracheal (I.T.) instillation of LPS challenge model. Lung injury was evaluated 6 h after LPS induction. Pretreatment with MAC markedly improved LPS-induced histological alterations and edema in lung tissues. Moreover, MAC also inhibited the release of pro-inflammatory mediators such as nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and IL-6 at 6 h in the bronchoalveolar lavage fluid (BALF) during LPS-induced lung injury. Furthermore, MAC reduced total cell number and protein concentrations in the BALF the pulmonary wet/dry weight (W/D) ratio, and myeloperoxidase activity and enhanced superoxide dismutase (SOD) activity in lung tissues. MAC also efficiently blocked protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and phosphorylation of mitogen-activated protein kinases (MAPKs) and inhibited the degradation of nuclear factor-kappa B (NF-κB) and IκBα. This is the first investigation in which MAC inhibited acute lung edema effectively, which may provide a potential target for treating ALI. MAC may utilize the NF-κB and MAPKs pathways and the regulation of SOD activity to attenuate LPS-induced nonspecific pulmonary inflammation.