Analysis of barium meal examinations performed at the Darwin Hospital on 742 non-Aboriginal patients showed that 82 (11.5%) had duodenal ulcers. A similar analysis of barium meal examinations performed on 94 Aboriginal patients at the same hospital did not reveal any duodenal ulcers. Aboriginal patients form 22% of the local population and 18% of the hospital admissions. Therefore, it is suggested that duodenal ulcer is an uncommon disease in the Aboriginal population of the Northern Territory of Australia.