The reactions of Co (II) and Ni (II) with alizarin red Shave been studied spectrophotometrically, in an attempt to establish the optimum conditions for determining micro amounts of cobalt and nickel. Alizarin red S forms a violet colored chelate wi th Co (II) at pH 7.0 ± 0.1 and orange colored chelate with Ni (II) at pH 7.0 ± 0.1 with A max 600 nm and 590 nm, respectively. The composition of both complexes is found to be 1:1. The effect of ionic strength and temperature on the stability of the complexes have also been studied.