Summary Gastric hemorrhage was produced in 93% of rats subjected to cold + restraint stress for 60 minutes. Mucosal damage was not evident and could not be induced by repeated stress periods. Anticholinergics, ganglionic blocking agents, certain central nervous system depressants and epinephrine reduced the incidence of hemorrhage. Gastric volume was reduced by cold + restraint in the pylorus-ligated and chronic gastric fistula rat, while gastric acidity was only reduced during stress in the fistula rats. The cold + restraint produced a marked hypothermic response and body temperature was depressed for 3 hours following the stress.