Dendrite-like cobalt selenide nanostructures were synthesized from cobalt and selenium powder precursors by a solvothermal method in anhydrous ethylenediamine. The as-prepared nanocrystalline cobalt selenide was found to possess peroxidase-like activity that could catalyze the reaction of peroxidase substrates in the presence of HO. A spectrophotometric method for uric acid (UA) determination was developed based on the nanocrystalline cobalt selenide-catalyzed coupling reaction between -ethyl--(3-sulfopropyl)-3-methylaniline sodium salt and 4-aminoantipyrine (4-AAP) in the presence of HO. Under optimum conditions, the absorbance was proportional to the concentration of UA over the range of 2.0-40 μM with a detection limit of 0.5 μM. The applicability of the proposed method has been validated by determination of UA in human serum samples with satisfactory results.