[en] Ternary palladium and platinum oxides NaPd_3O_4 and NaPt_3O_4 are studied theoretically using DFT. The calculated structural parameters and geometry are found consistent with the experiments. The mechanical properties analysis show that both compounds are elastically stable; anisotropic and reveal the ductile nature. Electronic cloud explain that the chemical bond between Na and Pd/Pt is ionic, whereas between O and Pd/Pt is covalent. The electronic band structures and densities of states demonstrate that these compounds are metals. The d-state splitting explains the origin of the electronic behaviour of these oxides. The optimised magnetic phase energies and magnetic susceptibility confirm that these oxides are paramagnetic metals.