Abstract. A method for the determination of the zinc (II) ion using a solution of 1-(2-hydroxy-1-naphthazo)-2-naphthol-4-sulfonic acid (HNNS) by extraction-spectrophotometric and cyclic voltammetric techniques is proposed. The optimal conditions were studied: distribution coefficient 0.98, choice of organic solvent, the ratio of organic to aqueous phases of 1:8, standard potential -0.51 V, and the detection limit of 0.387 µg/L. The reagent shows light absorption at 500 nm [1], contrast equal to 100 nm, and potential contrast of 0.98 V, which demonstrates the high sensitivity of the developed method. The developed method was compared with other analytical techniques and proved to be not inferior to them.