We studied the prevalence of Helicobacter pylori in Sudanese subjects with gastroduodenal inflammation. H. pylori was looked for in biopsy specimens taken from the antrum by two methods: rapid urease test [Campylobacter-like organism (CLO) test] and culture using Skirrow's selective supplement. One hundred subjects were studied. H. pylori was found in 80% of patients with gastritis, 56% of patients with duodenal ulcer, 60% of patients with duodenitis and 16% of normal control subjects. It was neither detected in patients with gastric ulcer, nor in patients with oesophagitis or in those with oesophageal varices due to schistosomiasis, when using culture. However, it was found in 50% of patients with oesophagitis, when using CLO test.