Helicobacter Pylori is believed to be an essential etiologic agent of type B chronic gastritis and peptic ulcer disease in humans. Recent reports have also suggested a role for these organisms in the development of gastric carcinoma and MALT-Lymphoma. A variety of diagnostic procedures are used for the identification of Helicobacter Pylori in clinical samples. 201 gastric biopsy (164 antral and 37 body biopsy specimens) were obtained from 164 patients with endoscopic abnormalities. These samples were studied for the detection of the presence of Helicobacter Pylori by histological staining (EE/Giemsa), immunohistochemistry and PCR by using a primer pair derived from the nucleotide sequence of the Urease A gene of Helicobacter Pylori. Specific amplification of a 411 base pair DNA fragment from all strain of Helicobacter Pylori tested was achieved. Of the 201 gastric biopsy analyzed, 63 (31%) were infected with Helicobacter Pylori on the basis of both histological and immunohistochemical staining, and 81 (41%) were positive with PCR (P < 0.001). Our results support a role for PCR in the rapid and highly sensitive and specific identification of Helicobacter Pylori in gastric biopsy specimens.