Background: Arrhythmias are a common occurrence in ACS. This study was undertaken to analyze the incidence, frequency and type of arrhythmias in relation to the site of infarction to aid in timely intervention to modify the outcome in MI and to study the significance of Reperfusion arrhythmias.Methods: 100 patients were evaluated. ECG and cardiac enzymes were studied. Arrhythmias complicating AMI in terms of their incidence, timing, severity, type, relation, reperfusion and results were studied.Results: Of the 100 cases, 74% were males and 26% females of which incidence being common between 4th to 7th decades of life. AMI was common in patients with Diabetes and Hypertension (23% each). Incidence of AWMI (58%) is higher than IWMI (40%). Out of all arrhythmias, Ventricular Tachycardia was seen in 24% cases with 50% mortality and preponderance to Antero Lateral Myocardial Infarction. Sinus Tachycardia was seen in 23% of cases with preponderance to Antero Lateral Myocardial Infarction and persistence of Sinus Tachycardia was a prognostic sign, mortality being 22%. Complete Heart Block and Sinus Bradycardia were seen with IWMI, incidence being 53.8% and 100% respectively. Bundle Branch Block was common in AWMI (31%) than IWMI (10%). Among 64 thrombo-lysed cases, 21 had Reperfusion Arrhythmias without any mortality, whereas remaining 43 without Reperfusion Arrhythmias had mortality of 18.6%.Conclusions: According to the study, Tachy-arrhythmias are common with Anterior Wall Myocardial Infarction and Brady-arrhythmias in Inferior Wall Myocardial Infarction. Reperfusion Arrhythmias are a benign phenomenon and good indicator of successful reperfusion.