Laser Doppler flowmetry (LDF) was used for endoscopic measurement of regional blood flow in 20 patients who had undergone previous gastric resection for peptic ulcer. Twenty-five patients with intact stomach and normal endoscopic findings were used as controls. In resected patients, the degree of enterogastric reflux gastritis was assessed by subjective grading and by morphological examination of biopsies from the region of the gastroenterostomy. In patients with an intact stomach, the average blood flow was significantly higher in the body of the stomach compared to the antrum (p < 0.001), without any significant differences between the greater and lesser curvature. In resected patients, the average blood flow in the gastric body remnant was markedly higher than in the region of the gastroenterostomy, but also significantly higher than the corresponding area of the gastric body in patients with an intact stomach (p < 0.01). The degree of gastritis in the region of the stoma of resected patients was often overestimated on subjective endoscopic assessments compared to morphological biopsy examinations. The degree of histological gastritis was not significantly correlated to blood flow levels of the gastroenterostomy. It is concluded that low gastric wall perfusion, impeding mucosal defense, does not seem to be a major factor in the development of enterogastric reflux gastritis in the resected stomach.