A systematic study of the growth of uniform vertically-aligned ZnO nanowires is presented. It is shown how, by careful control over the growth parameters, high quality nanowires of chosen morphology may be synthesized at low temperatures using electrodeposition. The key experimental parameters were the growth temperature, the ZnCl2 concentration in the electrolyte, the applied voltage and the thickness of the catalytic Au film. As a result of optimizing these parameters, ZnO nanowires with tailored dimensions were realized - an essential prerequisite for the use of such nanowires in functional nanoscale devices. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3567524] All rights reserved.