Introduction: Acute myocardial infarction is caused by a long-term myocardial ischemia.The ABO blood group exhibits a blood cell surface protein and an endothelial cell-associated Willebrand factor, and there is evidence that the blood type of individuals can determine the risk of thrombosis in advance.. Due to the importance and high prevalence of coronary artery disease, the association between myocardial infarction and ABO blood groups has not been proven so far and there are, even, controversial results; therefore, the present study was conducted to evaluate the relationship between ABO blood group and acute myocardial infarction. Method: The present case-control study was carried out at Amiralmomenin Hospital in Zabol. Samples were randomly divided in two groups, with blood serum of 300 patients with history of infarctionas the case group and that of 303 subjects with no history of infraction as the control group.The collected data was organized and analyzed using SPSS21 and descriptive and inferential statistics (ANOVA, Chi square, T test). All variables were considered significant in case of P<0.05 and the test was doublechecked. Findings: A total number of 603 patients, with an age range of 30 to 80 years, were analyzed in the present study; general blood group map of patients with myocardial infarction (case group) was like this: 91 subjects (30%) A, 71 subjects (24%) B, 35 subjects (11%) AB, and 103 subjects (35%) O. General blood group map of patients with no history of myocardial infarction (control group) was like this: 96 subjects (32%) A, 85 subjects (28%) B, 27 subjects (9%) AB, and 95 subjects (31%) O. the analysis of Chi-square findings showed that, with a confidence of 95% and 0.5%, there is a significant correlation between the incidence of myocardial infarction and the blood group (P<0.012) Discussion and conclusion: . The results of this study may have been obtained with respect to the environmental and genetic conditions and characteristics of the Zabul. These results may also be due to subunit blood groups that have not been evaluated in our study; however, given their limited number and the findings of the present research, it can be stated that O blood group in women can predispose a person to myocardial infarction. However, in order to collect more solid and comprehensive data, more studies are needed to be conducted on ABO blood groups in Iranian populations.