Upper gastrointestinal lesions associated with non-steroidal anti-inflammatory drug (NSAID) treatment are commonly implicated as the cause for iron deficiency anaemia in patients with rheumatic diseases. Such patients, however, may also have other causes for iron deficiency, including blood loss from the intestine. One hundred and four patients (mean age 58 years; male 21, female 83; smokers 14) with rheumatic disease (rheumatoid 91, others 13) and absent bone marrow iron stores (mean haemoglobin 83 g/l) were examined. At endoscopy 47 of 104 (45%) had upper gastrointestinal lesions (oesophageal ulcer 4, gastric ulcer 25, gastric erosion 13, duodenal ulcer 4, gastric ulcer and duodenal ulcer 1). Endoscopic healing was assessed in 23 patients with upper gastrointestinal lesions. Eighteen of 23 (78%) lesions healed with treatment. An improvement of anaemia occurred in 10 of 18 (56%) patients with healed lesions. Twenty three of 104 (22%) patients had dyspeptic symptoms. Ten of 23 (43%) patients with dyspepsia had an upper gastrointestinal lesion as compared with 30 of 81 (37%) patients without dyspepsia. A faecal occult blood test result was available in 53 patients. Of these, 13 were positive while 40 were negative. An upper gastrointestinal lesion was present in seven of 13 (54%) patients positive for the faecal occult blood test as compared with 14 of 40 (35%) negative for the test. Thus upper gastrointestinal lesions have previously been overestimated as the cause of iron deficiency anaemia in patients receiving NSAIDs. A positive faecal occult blood test or the presence of dyspepsia is not associated with upper gastrointestinal lesions in such patients.