Background and Objective: Helicobacter pylori are one of the most common gastrointestinal bacterium infections. This study was done to compare the urease test with Giemsa staining to detection of Helicobacter pylori infection in patients with gastric ulcer and gastritis.

Methods: This descriptive – analytic study was conducted on 601 patients' diagnosed with gastric ulcer and gastritis, whom under went endoscopy in 5th Azar hospital, Gorgan, Iran during 2008-12. Rapid urease test was immediately taken during endoscopy. Pathological examination, Giemsa staining on paraffin blocks and haematoxylin and eosin stain were done to assess either presence or absence of Helicobacter pylori.

Results: Based on biopsy results, Gastritis and gastric ulcer were diagnosed in 80.69% and 19.3%, respectively. In gastritis and gastric ulcer patients, there was a significant differences between urease test (91.5% and 90%, respectively) in comparison with Giemsa staining (91.5% and 90%, respectively) (P<0.05).

Conclusion: The study revealed that in primary diagnosis and screening of role of Helicobacter pylori in patients with gastric ulcer and gastritis, urease test is suitable than giemsa staining.