The copper dissolution was investigated in phosphate buffer in the presence of glyphosate using hydrodynamic voltammetry and chronoamperometry. The electrochemical studies showed that the addition of glyphosate in the phosphate buffer increases the electrochemical dissolution of copper electrode and this phenomenon was associated to the Cu(II) complexation by glyphosate. The apparent rate constant of the copper dissolution process (1.2 x 10(-2) cm mol(-1) s(-1)) and the diffusion coefficient of the complex (0.74 x 10(-5) cm(2) s(-1)), were obtained. It was observed that during the chronoamperometric experiments, in the absence of glyphosate, the electrode surface was covered by blue passive film, probably copper phosphate; nevertheless, in the presence of glyphosate, there was a gradual development of a blue color in the solution, indicating the copper dissolution and formation of the Cu(II)-glyphosate complex. (c) 2006 Elsevier B.V All rights reserved.