THE OBJECT of this report is to present a preliminary survey of our clinical and laboratory observations on the use of enterogastrone in the treatment of peptic ulcer as well as on its physiologic effects in man. Previous reports1 on the use of this substance in man have attempted to evaluate its therapeutic effectiveness largely on the basis of a comparison of the recurrence rate of duodenal or gastric ulcer before and after treatment with enterogastrone. Thus Greengard and his co-workerslb believed that their therapeutic trial of enterogastrone on 58 patients suffering from peptic ulcer over a period of years had demonstrated the probability that the drug is effective in preventing recurrences during the period of its administration and for a length of time thereafter as yet undetermined. No explanation of the action of enterogastrone was reported, but the opinion was expressed that possibly it increases the resistance