The association between Helicobacter pylori (HP) and gastritis is well established. As there is evidence that HP infection increases with age we reviewed the clinicopathological records of 119 consecutive patients aged 65-85 years (mean 71.1 years) on whom gastroscopy had been performed for dyspeptic symptoms. All patients had two antral biopsies--one was assessed for histological evidence of gastritis and the other was independently assessed for evidence of HP infection. Thirty-six patients (30%) had duodenal ulceration, of whom 32 (89%) had an associated HP-positive gastritis. Forty-nine patients (41%) had antral gastritis without ulceration, of whom 38 (78%) were HP positive and 11 (22%) were HP negative. Ninety-one per cent of HP-negative gastritis patients had a history of recent ingestion of non-steroidal anti-inflammatory drugs (NSAID) compared with 29% of HP-positive gastritis patients. Ten patients (8%) had normal antral mucosa but had evidence of reflux oesophagitis (one of these patients was HP-positive). Nineteen patients (16%) had normal antral mucosa and normal endoscopic findings and one of these was HP positive. We conclude that HP infection is associated with the majority of cases of symptomatic gastritis in elderly patients. HP-positive gastritis is associated with the majority of duodenal ulcers. The most important cause of HP-negative gastritis is NSAID ingestion.