Background. This study investigated the influence of feeding on gastric acid suppression in Helicobacter pylori-positive patients treated with intravenous infusions of proton pump inhibitors (PPIs) or with H-2-receptor antagonists (H-2-RAs) after bleeding from a gastric ulcer. Methods. Forty-nine H. pylori-positive patients with bleeding gastric ulcers (44 men and 5 women) were divided into four groups: one group received an H-2-RA while fasting, one group received an H-2-RA while eating regularly, one group received a PPI while fasting, and one group received a PPI while eating regularly. Intragastric pH was monitored during fasting and nonfasting to calculate the pH 3 and pH 4 holding times and the mean pH. Results. During a 24-h fast, the pH 3 and pH 4 holding times and the mean pH were significantly higher in patients administered omeprazole (PPI; 93.2 +/- 9.2%, 90.6 +/- 11.1%, and 6.9 +/- 0.6, respectively) than in those administered ranitidine (H-2-RA; 61.0 +/- 27.5%, 55.8 +/- 29.1%, and 4.8 +/- 1.3, respectively; P < 0.001 for all). Results were similar during feeding (PPI meal, 98.9 +/- 2.6% 98.3 +/- 3.7%, and 6.9 +/- 0.3; H,RA meal, 59.8 +/- 17.6%, 49.7 +/- 18.0%, and 4.3 +/- 0.7, respectively; P < 0.001 for all). In addition, the pH 3 and pH 4 holding times and the mean pH in the H-2-RA meal group were not significantly lower than those in the H-2-RA group (P = 0.999, P = 0.865, and P = 0.687, respectively). The values in the PPI and PPI meal groups were similar (P = 0.872, P = 0.777, and P > 0.999, respectively). Conclusions. Gastric acid suppression during the administration of an H-2-RA or a PPI soon after the cessation of gastric bleeding was scarcely affected by feeding. It may well be that H. pylori-positive patients with bleeding gastric ulcer can resume a regular diet and return to work soon after bleeding ceases.