Aim: To detect arrhythmia during hospitalization of patients with acute coronary syndrome and to correlate the association between arrhythmia and patient outcome. Introduction: Acute coronary syndrome represents a Global Pandemic, and is intimidating large as the new epidemic afflicting population worldwide, especially in the Indian sub-continent. Studies have shown that arrhythmias are important predictors of poor outcome in patients with ACS and are associated with higher in-hospital mortality. So, ECG is of great value in patients with acute MI and is essential for risk stratification and selection of optimal management. Methods: A Prospective clinical study consisting of 100 patients of acute coronary syndrome were admitted in ICCU of Mandya Institute of medical Sciences, Mandya who are aged between 18 –50yrs during the period of study (January 2018 to December 2018, a period of 12 months) were taken to determine the occurrence of arrhythmia, its predictors and outcome. Patients were assessed with Characteristic history, ECG criteria and Elevated cardiac enzymes. Results: A total of 100 patients are taken, on admission to the intensive coronary care unit at Mandya Institute of Medical Sciences, Mandya. They included 56 males and 44 females (52%).