Backgrounds: Helicobacter pylori infections vary in severity and virulence in different populations for various reasons. There are different H. pylori strains with varying degrees of virulence. The genetic diversity of H. pylori strains in gastritis patients in different areas has not been well understood. This study aimed to evaluate the prevalence rate and different genotypes of H. pylori strains in clinical specimens of patients with gastritis in Ilam, Iran. Materials & Methods: Saliva and gastric biopsy samples were collected from 81 patients (55 males and 26 females in the age range of 20 to 90 years) referring to Ilam medical centers.After DNA extraction, the prevalence of H. pylori as well as vacA, cagA, and ureC genes was evaluated using PCR, and then each vacA-positive sample was further evaluated for m1m2 and s1s2 variants. Findings: The cagA and vacA genes were found in 27 (71%) and 36 (94.7%) H. pylori-positive samples, respectively. The cagA gene was detected in patients with gastric pain (44.4%) and anorexia (18.51%). Also, the results showed that the vacA s2m2 genotype and m2 allele were present in 32.9% of H. pylori isolates. Moreover, s2m2 and s1m2 genotypes were detected in 42.1 and 26.3% of vacA-positive samples, respectively. The lowest frequency was related to the m1 allele (17.18%). Conclusion:This study results indicate a plausible relationship between the presence of some genotypes of H. pylori and the progression of gastritis, suggesting these markers as promising biomarkers to predict the disease severity.