It has been reported that 30-72% of patients with duodenal ulcer disease also have esophagitis. However, many of these reports included patients who had severe or complicated ulcer disease, so that the high prevalence may reflect pyloric stenosis or gastric hyper-secretion. The objective of this study was to determine the prevalence of esophagitis in unselected patients with duodenal ulcer disease or ulcer-like dyspepsia. A prospective study of endoscopic and histological esophagitis in consecutive patients with either duodenal ulcer disease or with ulcer-like dyspepsia. Of 27 patients with duodenal ulcer disease, 33% had endoscopic esophagitis, 26% had histological esophagitis, and 48% had esophagitis by either criterion. Of 66 patients with ulcer-like dyspepsia, 35% had endoscopic esophagitis, 47% had histological esophagitis, and 62% had esophagitis by either criterion. Esophagitis was independent of patients' Helicobacter pylori status. Esophagitis is common in patients with duodenal ulcer disease, and the prevalence is similar in patients with ulcer-like dyspepsia. In addition to causing heartburn, esophagitis may also be cause ulcer-like epigastric pain. Concomitant esophagitis may account for the persisting or recurring dyspepsia that has been reported in up to one-third of duodenal ulcer patients after successful eradication of H. pylori.