Biopsies from 60 patients with dyspepsia and endoscopically abnormal first part of duodenum were examined. The main endoscopic findings were duodenitis (35 cases), chronic ulceration (eight) and abnormal mucosal patterns (17). The latter included mucosal atrophy, thickening, irregularity, nodularity and polypoid formation. The main histological findings were duodenitis (40), gastric metaplasia (42) and gastric heterotopia (seven). The first two were commonly seen together. Heterotopia was not associated with inflammation. Good correlation existed between endoscopic and histological findings.