The specific trophic effects of gastrointestinal hormones on gastric function are now recognized. In addition, pituitary, thyroid and adrenal hormones play an important role in maintaining over all gastric function. The majority of studies regarding hormonal effects on the stomach, however, have been carried out only in experimental animals. This paper reports a patient with gastric atrophy and hypopituitarism. Following therapy of the hypopituitarism with cortisone acetate, sodium levothyroxine and testosterone, the following observations were made: serum gastrin increased 137%; mucosal DNA synthesis and content and gastric acid secretion all increased. These data indicate in this one patient the role of these hormones in gastric function.