Specialised columnar epithelium (SCE), a form of intestinal metaplasia usually found in Barrett's oesophagus, cannot be distinguished endoscopically from normal gastric epithelium. Endoscopists seldom obtain biopsy specimens from a normal-appearing gastro-oesophageal junction, and therefore short segments of SCE in this region may go unrecognised. We studied patients who had short segments of SCE at the gastro-oesophageal junction. All patients scheduled for elective endoscopic examinations in our general endoscopy unit, irrespective of indication, were questioned for symptoms of gastro-oesophageal reflux disease. At endoscopy, severity of oesophagitis was graded, and biopsy specimens obtained from the squamocolumnar junction, irrespective of its appearance or location in the oesophagus. Among 142 patients without endoscopically apparent Barrett's oesophagus, 26 (18%) were found to have SCE. All patients with SCE were white, and the male/female ratio was 1.9. In contrast, non-whites accounted for 14% of the 114 patients without SCE and the male/female ratio was 0.8. The groups did not differ significantly in the frequency of symptoms and endoscopic signs of gastrooesophageal reflux. We conclude that adults frequently have unrecognised segments of SCE at the gastro-oesophageal junction; this may underlie the rising frequency of cancer of the gastrooesophageal junction in the USA and Europe.