Nickel(II) react with 2-Hydroxy-4n-butoxy-5-bromo acetophenone oxime (HBBAO) to give dark green precipitates, which are extractable into chloroform layer. They exhibits λmax at 400 nm and 600 nm and obey Beer’s law in the concentration range 29.36-234.84 μg/ml. Job’s method for continuous variation, Yoe and Jones’ mole ratio method and the slope ratio method show metal:ligand ratio in complex to be 1:2. The stability constant of the complex is found to be 5.49 X107. The effect of foreign ions has also been investigated in the determination of metal. The reagent has also been found to give quite satisfactory results for Ni(II) present in synthetic mixtures.