The aim of present study was to evaluate the cardioprotective activity of leaf extract of L. siceraria against the Isoproterenol induced cardiotoxicity in rats. The leaf extract of Lagenaria siceraria (LSLE) was prepared using 70% ethanol (hydroalcoholic) using soxhlet apparatus. Extract was administered to Male wistar albino rats. Blood was collected & Serum was separated and used for measurement of cardiac marker enzymes like, CK-MB, LDH, Cardiac Troponin I and serum parameters like AST, ALT and ALP. hearts were isolated from rat, which were used for the histopathological studies and for determination of total proteins and antioxidant parameters like SOD, GSH and for the MDA content for Lipid peroxidation.