Nickel oxalate nanowires were produced by the reaction of nickel thin films electrochemically deposited on ITO glass in ethanolic oxalic acid. Their densities and lengths were strongly influenced by the thickness and roughness of the deposited nickel layers. The nickel layers became thicker with increasing deposition time, producing longer nanowires. Increasing roughness of the nickel layer led to shorter and denser nanowires. The total surface area of the nickel oxalate nanowires can be manipulated by the thickness and surface roughness of the electrochemically deposited film. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3529938] All rights reserved.