Abstract.Cathodic adsorptive stripping voltammetry (CASV) was applied for the determination of rutin in pharmaceuticals, human urine, and blood serum. An electrochemical stripping procedure for trace measure-ments of rutin was developed based on the adsorption of the Cu 2þ -rutin complex on a hanging mercury drop electrode and applied to the quantification of the drug. Cyclic voltammetry was used to characterize the inter-facial and redox behavior of the adsorbed Cu 2þ -rutin complex. Experimental and instrumental parameters for quantitative determination were optimized, and a detection limit of 4.910 9 molL 1 in presence of Cu 2þ-ions for quantification of rutin under optimum conditions was derived. The sharp peak of the adsorbed Cu 2þ -rutin complex associated with an effective inter-facial accumulation of this compound facilitates the determination of rutin in biological fluids with good recoveries. The degree of interference from potentially present metal ions and organic compounds on the CASV signal for Cu 2þ -rutin complex was evaluated.