A Meckel's diverticulum is an unusual site of gastrointestinal bleeding in adults. Bleeding often results from ulceration of ileal mucosa that lies adjacent to ectopic gastric mucosa. We report on a 27-yr-old man who bled from a Meckel's diverticulum after receiving oral ibuprofen, a nonsteroidal antiinflammatory drug. Examination of the resected diverticulum revealed fundal-type gastric mucosa with inflammation, submucosal hemorrhages, erosions and ulceration in the absence of Helicobacter pylori. The ileal mucosa was spared in this patient. These features suggest that oral ibuprofen caused damage to the ectopic gastric mucosa, precipitating significant hemorrhage. This is the first report in the English literature of such an occurrence.