Cobalt bis(oxalato)nickelate pentahydrate, Co[Ni(C2O4)2]5H2O and cadmium bis(oxalato)nickelate tetrahydrate, Cd[Ni(C2O4)2]4H2O have been synthesized and characterized by elemental analysis, reflectance and IR spectral studies. Thermal decomposition studies (TG, DTG and DTA ) in air showed that both the compound of cobalt and cadmium produced the oxide, MNiOx (x=3 for M=Co; x=2 for M=Cd ) at 325 and 360C respectively. DSC studies in nitrogen attributed only the mixture of both the metal at the end.