The present work describes the stress degradation behavior of Levosimendan as per ICH guidelines. Under thermal and photolytic conditions drug had a fair stability and in other stress conditions degradation products (DP) were observed. Initial identification of the DP was performed by UPLC-MS and isolation by MDAP. Various 1 D and 2 D NMR experiments along with supporting FT-IR and HRMS data were performed to characterize the DP. A novel degradant product observed in acidic conditions was isolated and characterized as (R,Z)-2(2-(4-(4-amino-2-methyl-4-oxobutanoyl) phenyl) hydrazono)-2-cyanoacetic acid (DP-1) with molecular formula C14H14N4O4. Additionally, two more DP were observed in both basic and peroxide conditions which are basically reported impurities. (R,E)-2-amino-N’-(4-(4-methyl-6-oxo-1,4,-5,6-tetrahydropyridazin-3-yl)phenyl)-2-oxoaceto hydrazonoyl cyanide (DP-2), a Cyano to amide converted product and (R)-5-methyl-6-phenyl-4,5-dihydropyridazin-3(2H)-one (DP-3) formed as result of cleavage of aryl nitrogen bond of benzene substituted dicyano hydrazine.