Aims: To evaluate the sensitivity and specificity of different symptoms in erosive reflux oesophagitis and Barrett's oesophagus. Methods: The presence of reflux symptoms was compared between a case population of 306 patients with endoscopically determined erosive reflux oesophagitis, 235 patients with biopsy-proven Barrett's oesophagus and a control population of 198 subjects without reflux disease. Results: Heartburn at any time and heartburn at night represented the only two symptoms to be simultaneously sensitive and specific. Symptoms that were induced by various foods, such as fat, tomato, chocolate, citrus or spices, tended to cluster in the same sub-group of patients. Similarly, heartburn induced by exercise, lying down or bending over tended to occur in the same sub-groups. The frequency of symptoms was influenced more by the presence of mucosal erosions than by the presence of Barrett's oesophagus. Reflux symptoms occurred more frequently in the presence rather than the absence of Barrett's oesophagus, and in long segment rather than short segment of Barrett's mucosa. Conclusions: Endoscopic inspection of the oesophageal mucosa remains the only certain method by which to reliably diagnose erosive reflux oesophagitis and Barrett's oesophagus.