To evaluate the association of Helicobacter pylori infection with gastroduodenal ulceration and symptoms in rheumatoid arthritis patients chronically ingesting nonsteroidal anti-inflammatory drugs (NSAIDs), a population-based study was performed. Residents of Olmsted County, Minnesota, and surrounding counties, 40 years of age and over with active rheumatoid arthritis taking therapeutic dose of NSAIDs daily for 6 months or more were evaluated (n = 50). An endoscopic score from 0 to 5 was assigned and independently confirmed. Biopsies were obtained from the antrum and gastric body for the presence of H. pylori. A symptom score based on the frequency and severity of dyspeptic symptoms was calculated. Substantial mucosal injury (greater than or equal to grade 2) was observed at endoscopy in 33 patients (66%); 14 (28%) had chronic ulcers. Eleven of the community patients with rheumatoid arthritis (22%) were H. pylori positive; adjusting for age, the prevalence of H. pylori was not significantly different to that in 67 health controls (25%). One or more upper gastrointestinal symptoms were reported by 19 of the community patients (38%). Adjusting for age, community rheumatoid arthritis patients with H. pylori were not more likely to have visible mucosal damage or dyspepsia, but were significantly more likely to have histological gastritis (P less than 0.01). The results suggest that, in primarily asymptomatic persons from the community with rheumatoid arthritis taking daily NSAIDs for 6 months or more, H. pylori infection is not related to the severity of visible mucosal injury.