AIM:The mostly known genotypic virulence features,ofH.pylori are cytotoxin associated gene A (cagA) andVacuolating cytotoxin gene A (VacA).We investigated theassociation of these major virulence factors with ulcer andnon-ulcer dyspepsia in our region.METHODS:One hundred and forty two dyspeptic patientswere studied (average age 44.8±15.9 years,range 15-87years,64 males and 78 females).Antral and corpus biopsieswere taken for detecting and genotyping of H.pylori.107patients who were H.pylori positive by histologicalassessment were divided into three groups according toendoscopic findings:Duodenal ulcer (DU),gastric ulcer (GU)and non-ulcer dyspepsia (NUD).The polymerase chainreaction (PCR) was used to detect CagA and VacA genes ofH.pylori using specific primers.RESULTS:H.pyloriwas isolated from 75.4% (107/142) ofthe patients.Of the 107 patients,66 (61.7%) were cagA-positive and 82 (76.6%) were VacA-positive.CagA genewas positively associated with DU and GU (P<0.01,P<0.02),but not with NUD (P>0.05).Although VacA positivity in ulcerpatients was higher than that in NUD group,the differencewas not statistically significant (P>0.05).CONCLUSION:There is a significantly positive associationbetween CagA genes and DU and GU.The presence ofVacA is not a predictive marker for DU,GU,and NUD inour patients. AIM: The mostly known genotypic virulence features, of H. pylori are cytotoxin associated gene A (cagA) and vacuolarting cytotoxin gene A (VacA). We investigated the association of these major virulence factors with ulcer andnon-ulcer dyspepsia in our region. METHODS: One hundred and forty two dyspeptic patients were studied (average age 44.8 ± 15.9 years, range 15-87 year, 64 males and 78 females). Central and corpus biopsieswere taken for detecting and genotyping of H.pylori.107patients who were H.pylori positive by histologicalassessment were The polymerase chain reaction (PCR) was used to detect CagA and VacA genes of H. pylori using specific primers .RESULTS (PCR) was used to detect CagA and VacA genes of H. pylori using specific primers Of the patients. Of the 107 patients, 66 (61.7%) were cagA-positive and 82 (76.6%) were VacA-positive. CaC gene positively associated with DU and GU ( P <0.01, P <0.02), but not with NU D (P> 0.05). Although VacA positivity in ulcer patients was higher than that in NUD group, the difference was not significant significant (P> 0.05). CONCLUSION: There is a significant positive association between CagA genes and DU and GU. not a predictive marker for DU, GU, and NUD inour patients.