Gastric secretion was studied in two groups of rats in which pyloric ligature with wire was previously peformed. One of the groups was acutely bled until hypovolemia. The following parameters were checked: gastric volume, acid and pepsin secretion, Pu/g of stomach, chloride, potassium, and sodium. A significant decrease in volume, acid and pepsin secretion, Pu/g of stomach and chloride and increase in potassium in the hypovolemic rats found. There was no significant change in sodium concentration. There was no significant difference in the pepsinogen concentration in gastric mucous between both groups of rats.