BACKGROUND Gastritis has a broad histopathologic and topographical spectrum and leads to different patterns of disease. The introduction of the Sydney system made it possible to grade histological parameters, identify topographic distribution and provide etiological information which would help to generate reproducible and clincally useful diagnoses. The aim of this study was to determine the prevalence of Helicobacter pylori in non-ulcer dyspepsia, duodenal ulcer and gastric ulcer; and to assess the histopathologic features associated with chronic gastritis. METHODS Gastric antral biopsy specimens from 200 patients were examined for the prevalence of H. pylori, and were classified and graded histologically. RESULTS The overall colonization rate of H. pylori was 44%. The colonization rates were 85%, 67% and 41% in patients with duodenal ulcer, gastric ulcer and non-ulcer dyspepsia respectively. There was not much difference between the degree of atrophy and intestinal metaplasia in H. pylori positive and negative cases. CONCLUSIONS Helicobacter gastritis is the commonest type of gastritis present in patients presenting with dyspeptic symptoms. It is more common in patients presenting with duodenal ulcer. Adequate sampling is a must for accurate diagnosis of H. pylori colonization.