Cadmium sulfide (CdS) nanowires were electrosynthesized within the pores of the anodic alumina membranes (AAM) using underpotential deposition (UPD) through an electrochemical co-deposition at room temperature (25 degrees C). The nanowire arrays were grown from an aqueous solution of CdSO4, ethylenediaminetetraacetic acid (EDTA), and Na2S at pH 4.0. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). UV-vis absorption spectroscopy, and energy dispersive spectroscopy (EDS) were employed to characterize the nanowires. These nanowires have uniform diameters of approximately 90 nm, and their lengths are up to 7 mu m. XRD analysis reveals that the electrosynthesized nanowires deposited at -500 mV (vs. Ag/AgCl) have a preferential orientation along (1 1 0) direction for hexagonal crystal. Electrochemical and EDS results of the deposits confirm that the atomic ratio of Cd to S is very close to 1:1 stoichiometry. UV-vis absorption measurement shows a blue-shifted absorption at 488 nm because of the quantum confinement at low dimensions. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.