The effect of gluconate on the deposition rate and the deposit composition was examined at low pH of solution. The deposition rate exhibit a maximum and the content of copper present a minimum when the gluconate concentration changes between 0 and 40 g/l. The kinetic study carried out by cyclic voltammetry and electrochemical impedance showed that the gluconate acts on the anodic and cathodic reactions. The activation energy of the alloy deposition was determined. In addition, gluconate does not affect the crystallinity of the Ni-Cu-P deposit. (c) 2007 Elsevier Ltd. All rights reserved.