Two hetero-bimetallic precursors, [Co(en) 3 ] 2 [Ni(edta)] 3 and [Ni(en) 3 ][Co(edta)] 2 (en = ethylenediamine and edta 4– = ethylenediaminetetraacetate anion), were synthesized in an aqueous solution. For the first time, this type of hetero-bimetallic precursors was used for the preparation of NiCo 2 O 4 (nickel cobaltite) nanospinels by calcination method. The results clearly showed the effect of different precursors on the final nanoparticles. The actual yield for the preparation of the nanospinels from [Ni(en) 3 ][Co(edta)] 2 precursorwas greater than the yield for [Co(en) 3 ] 2 [Ni(edta)] 3 precursor. The nanospinels were characterized using different techniques such as FT-IR, UV-Vis, zeta potential measurement, X-ray diffraction analysis (XRD), field-emission scanning electron microscopy (FE-SEM), and Brunauer-Emmett-Teller (BET) surface area measurement. Also, the catalytic activity of NiCo 2 O 4 nanospinels was investigated for the oxidation of Rhodamine B to innocuous compounds at room temperature in water. The oxidation reaction was carried out in a batch reactor at ambient temperature and pressure with different reaction parameters such as reaction time, dye concentration, and catalyst loading. The cationic dye Rhodamine B was almost completely oxidized in the optimized reaction conditions.In addition, the catalysts could be recovered and reused successfully several times.