Different dilutions (15, 30, 60, and 95% v/v) of ethanol in water were administered to rats by stomach-tube. In well-nourished animals negligible damage to the mucosa of the stomach was observed at the lower concentrations. Occasional hemorrhages and erosions of the gastric mucosa were seen at concentrations of 60% or stronger. In grossly malnourished rats, minimal gastric lesions were encountered more frequently and at lower concentrations of alcohol (30%). Ulceration was not observed, even when 95% ethanol was given to the deficient rats. No lesions were found in the intestinal tract, even in the deficient rats, except for an occasional trace of hemorrhage and (or) erosion of the duodenal mucosa.