Gastric secretion stimulated by a 100-g meat meal was inhibited by oleic acid and triolein and the inhibition correlated with absorption of the respective lipids in dogs with vagally innervated gastric pouches. Twenty-six milliliters of lipid were infused into the duodenum at 0.76 ml/min through a duodenal fistula starting 5 min before feeding. Gastric secretion was collected every 30 min and analyzed for acid and pepsin concentrations. Paraffin oil infused at the same rate gave results similar to feeding alone. Lipid absorption was determined by measuring venous plasma radioactivity at 1, 2, 3, 4, and 6 hr after feeding and infusing of C14-labeled oleic acid or triolein. Lipid in intestinal content for 3 hr after feeding was determined in acute experiments. The duration of gastric inhibition was longer and the absorption was slower with oleic acid than with triolein.