Background: Kidney dysfunction affects cardiovascular outcome in patients with acute myocardial infarction. Creatinine, urea nitrogen and urea nitrogen-to-creatinine ratio (UCR) are kidney biomarkers routinely measured in patients with acute myocardial infarction. Their implication in acute myocardial infarction has not been validated. Aims: The study aims to investigate the association between urea nitrogen, creatinine and UCR and in-hospital adverse cardiac events in patients with acute myocardial infarction. Methodology: The study design was cohort. Subjects were patients with acute myocardial infarction. Blood urea nitrogen and creatinine were measured on admission. The UCR was calculated as ratio of urea nitrogen to creatinine. The observation was performed during hospitalization in ICCU to detect the adverse cardiac events, i.e. death, acute heart failure, cardiogenic shock, reinfarction and rescucitated ventricular arrhytmia. The ROC curve was designed to determine the cut-off point of high urea nitrogen, creatinine and UCR. The bivariate and multivariable analysis were performed to establish the independent predictors of adverse cardiac events. A p value < 0.05 was a limit of statistics significance. Results: The subjects of this research were 424 patients. Among them, 96 subjects (22.6 %) developed in-hospital adverse cardiac events. Subjects with adverse cardiac events had significantly higher level of urea nitrogen, creatinine and UCR. The bivariate analysis showed that high urea nitrogen, high creatinine and high UCR were associated with adverse cardiac events. The multivariable analysis showed only high urea nitrogen as an independent predictor for adverse cardiac events (adjusted OR 3.14 (95 % CI:1.37-7.19, p value 0.007)). Conclusion: High urea nitrogen, creatinine and UCR were associated with increased in-hospital adverse cardiac events. Only high urea nitrogen was an independent predictor for in-hospital adverse cardiac events in patients with acute myocardial infarction.