The variation in the healing and the relapse rates of peptic ulcer disease has led to the search for other factors in the pathogensis of peptic ulcer disease. Helicobacter pylori is believed to be responsible for these different patterns of healing. The results of a study to detect Helicobacter pylori in Sri Lankan patients having duodenal ulcer, gastric ulcer, gastritis and non-ulcer dyspepsia are presented in this paper. The method employed was the urease test which detects the urease enzyme of H. pylori in gastric mucosal biopsies taken during upper gastrointestinal endoscopy. There is a high incidence in those with gastritis and duodenitis.