Aim: To assess serum potassium levels in Acute myocardial infarction patients. Materials & methods: 50 confirmed cases of AMI were included in the present study. Another set of 50 age and gender-matched healthy subjects were taken as control. Collection of venous blood samples was done in the study group on the day of admission within 12 hours from anticubital vein with all aseptic precautions in plain and vacutainers for the purpose of routine baseline blood investigations. For serum potassium levels, blood was allowed to clot at room temperature for half an hour and then centrifuged at 3000 rpm for five minutes. The serum separated was used for the estimation of serum potassium levels. Results: Mean serum potassium levels among the patients of the study group and control group were 3.89mEq/L and 4.56 mEq/L respectively. While comparing statistically, significant results were obtained. Out 50 patients of the AMI group, hypokalaemia was seen in 24 percent of the patients. Conclusion: It is recommended that potassium levels which affect the clinical outcomes in patients of acute myocardial infarction should be monitored, and potassium replaced whenever required.