Aim: To determine the risk factors associated with patients of acute myocardial infarction. Materials & Methods: This study was a nested case-control study was conducted in the Department of Medicine, Narayan Medical College & Hospital Sasaram, Bihar. The patients were selected from the OPD/in-hospital patients. A total of 1300 patients who fulfilled the inclusion criteria were included in the study. Study participants were randomly allocated to two groups: cases (n=650) & control (n=650) groups respectively. The study duration was one year. Results: Case patients had a mean (SD) age of 65.4 (11.2) years and control individuals had a mean (SD) age of 65.7 (11.8) years. Compared with controls, in-hospital AMI cases were significantly more likely to occur in intensive care unit settings (24.8% vs. 8.2%) and to have a history of atherosclerotic disease (i.e., myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft, cerebrovascular disease, or peripheral vascular disease). Coronary disease risk factors of hypertension, hyperlipidemia, and diabetes were also more common in patients with AMI.