The potentials of zero charge (pzc) of copper monocrystalline electrodes of three basal indices, namely (1 1 1), (1 1 0) and (1 0 0) and a polycrystalline electrode have been determined by impedance spectroscopy methods, in the frequency range of 1-100 Hz. Experiments were carried out in perchlorate solutions. The values of the pzc for (1 1 1), (1 0 0) and (1 1 0) were equal to -0.70, -0.73 and -0.75 V vs SHE electrode, respectively. This sequence of pzc is the same as for other monocrystalline electrodes of fee structure, i.e. the pzc is most negative for the open (1 1 0) and less negative for the close packed (1 1 1) structures, though the differences are much smaller than reported by others. A dependence of the pzc on the pH of the solution was observed. (C) 2003 Elsevier B.V. All rights reserved.