Background & Objectives: Coronary artery disease is the main cause of mortality in developing and industrial countries. Recently the involvement of infectious agents as a risk factor for Acute Coronary syndrome is drafted. So this study was designed to investigate the probable association between Acute Coronary syndrome and Helicobacter pylori infection.

  Methods: This case-control study was carried out on 300 hospitalized patients with the diagnosis of Acute Coronary syndrome (UA and MI) and 300 hospitalized patients without the history of coronary heart disease. Anti Helicobacter pylori Antibody level was determined by as an indicator of infection history. Using chi-square and t- test the results were analyzed in SPSS software.

  Results: Results showed that 79 patients (26.3%) in control group and 122 patients (40.6%) in case group were seropositive and the difference was significant. Relationship between cronory diseases risk factors and levels of IgG was not significant. Also the results showed that the rate of hypertension in seropositive patients in case group was significantly upper than control group.

  Conclusion: Regarding the findings of this study we can conclude that Helicobacter pylori infection probably is a risk factor for Acute Coronary Syndrome. Thus, further studies are needed to elucidate the association between Helicobacter pylori infection and Acute Coronary Syndrome.