This study was designed to investigate the cardioprotective activity of poly herbal formulation Medohar vati in isoproterenol (ISO)- induced myocardial necrosis in rats. Animals were treated with Medohar vati (150 and 300 mg/kg for 21 days) and Carvedilol (10mg/kg for 7 days) to the rats treated with ISO (85 mg/kg, sc) on the 22th and 23rd days. The group only treated with ISO demonstrated elevated level of Lactate dehydrogenasa (LDH), Creatine kinase (CK-MB) and CK- NAC in serum which was restored with all the prophylactic treated groups such as Carvedilol and both the doses of Medohar vati. Similarly the abnormal electocardiographic changes like RR and PR interval, QRS duration, QT segment was normalized by Carvedilol and with both the doses of Medohar vati. The results were supported by the histopathological analysis. To conclude Medohar vati was found to be cardioprotective against ISO induced myocardial damage in rats.