ZnO nanostructured films fabricated by electrochemical deposition exhibit a variety of morphologies. Understanding their respective nucleation and growth mechanisms requires in situ techniques. A time-resolved X-ray absorption and fluorescence method is described, which adequately captures both processes and illustrates differences in the growth rates for films deposited at different potentials. In so doing, the new method has significant advantages over a previous method of continually scanning across the near-edge region of the absorption spectrum while the film was being deposited. (C) 2007 Elsevier B.V. All rights reserved.