We investigated regional variation in resting focal gastric mucosal blood flow obtained by endoscopic laser-Doppler flowmetry in patients with symptoms of dyspepsia or peptic ulcer (N = 12) and asymptomatic healthy volunteers (N = 6). Mucosal blood flow was measured for 1 min at the duodenum (first part), prepylorus, antrum and body (anterior and posterior walls), angularis, mid-greater curvature, fundus, and distal esophagus. At all sites, mean +/- SE blood flow in patients was 71.88% of the corresponding value in volunteers (1.15 +/- 0.10 and 1.60 +/- 0.13 volts, p less than 0.02, t test). In both groups, blood flow was highest in the fundus, followed by the body and lowest in the antrum; the angularis had a high blood flow, second only to the fundus. There was no correlation between age and blood flow. We conclude that regional variation in resting gastric mucosal blood flow exists in health and disease.