Background: There is a well-established relationship between myocardial infarction and infection. Multiple articles describe the increased risk of myocardial infarction, both type 1 and 2, following an infectious process. However few articles have described the relation between concomitant myocardial infarction and infections on same admission mortality and complications. Methods: The aim is to assess the effect of an acquired or concomitant infection on complications and mortality during hospitalized cases of myocardial infarction. 1197 patients of different types of myocardial infarction were studied in correlation to infectious processes. Cultures from different sites were collected and isolation of various bacterial agents were studied. Mortality and various complications were compared between infected and non-infected subjects. Pearson's chi squared test was used to compare percentages (or the Fisher exact test when expected values were lower than 5). Moreover, means were compared through ANOVA, after checking data normality and homoscedasticity. A likelihood ratio backward stepwise method was used to conduct dichotomous logistic regressions, taking dichotomous outcomes as dependent variables, and sociodemographic and biological characteristics as independent variables (potential confounders).Results: Wound, sputum, blood and urine infections were associated with increased same admission mortality and complications. Microorganisms were then studied alone regardless of the site of infection and it was shown that Escherichia Coli, Escherichia Coli ESBL, Candida Albicans, Pseudomonas Aeruginosa and Staphylococcus of any type were significantly associated with same admission complications when associated with myocardial infarction. Length of stay was significantly elevated in patients with concomitant infection and it increased with the addition of positive cultures from different sites. Conclusion: Concomitant infections with myocardial infarction significantly increase the risk of same admission complications, mortality and length of stay regardless of the site of infection and type of microorganisms.