Previous studies of gastric secretory function and serum gastrin levels in patients with chronic renal failure (CRF) have yielded conflicting results. In a study of 30 patients on regular hemodialysis, serum gastrin levels were higher than normal (p < 0.05), and the gastric secretory response to pentagastrin was normal for the group as a whole. There were, however, 8 patients who were hypochlorhydric (4 achlorhydric) and 7 who were hyperchlorhydric. The patients with gastric hyposecretion were older, predominantly male and this group was associated with the highest gastrin levels as well as the highest incidence of gastrointestinal hemorrhage. Chronic gastritis is thus more common in CRF than generally believed and may be responsible for much of the morbidity from gastrointestinal complications during hemodialysis.