Tumor necrosis factor-α (TNF-α) production is a critical factor in the pathogenesis of alcoholic liver injury. Both oxidative stress and endotoxin have been implicated in the process of alcohol-induced TNF-α production. However, a cause-and-effect relationship between these factors has not been fully defined. The present study was undertaken to determine the mediators of acute alcohol-induced TNF-α production using a mouse model of acute alcohol hepatotoxicity. Alcohol administration via gavage at a dose of 6 g/kg to 129/Sv mice induced hepatic TNF-α production in Kupffer cells as demonstrated by measuring protein levels, immunohistochemical localization, and mRNA expression. Alcohol intoxication caused liver injury in association with increases in plasma endotoxin and hepatic lipid peroxidation. Treatment with an endotoxin neutralizing protein significantly suppressed alcohol-induced elevation of plasma endotoxin, hepatic lipid peroxidation, and inhibited TNF-α production. Treatment with antioxidants, N - acetyl-l-cysteine, or dimethylsulfoxide, failed to attenuate plasma endotoxin elevation, but significantly inhibited alcohol-induced hepatic lipid peroxidation, TNF-α production and steatosis. All treatments prevented alcohol-induced necrotic cell death in the liver. This study thus systemically dissected the relationship among plasma endotoxin elevation, hepatic oxidative stress, and TNF-α production following acute alcohol administration, and the results demonstrate that oxidative stress mediates endotoxin-induced hepatic TNF-α production in acute alcohol intoxication.