The effect of acute ethanol ingestion (5 g/kg) by fasted rats, or chronic treatment in fed animals, revealed a significant decrease in the content of reduced glutathione of the liver and kidney. No changes were observed in reduced glutathione levels of the pancreas, stomach or spleen in the acute model. In this condition, the time course study of the decrease in reduced glutathione levels showed a progressive effect in the liver and a rapid and constant effect in the kidney.