A new type of self-assembled zinc oxide (ZnO) nanostructure has been prepared by electrochemical anodization of zinc foil in NaOH aqueous electrolyte. Under optimized anodization conditions, well defined nanorods were obtained with a stacking nanoparticle layer on the top and straight cellular structures underneath. The relationships between the morphology of the nanostructures and anodization parameters were studied in detail through field-emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD) and energy-dispersive X-ray spectrometry (EDS). The experimental results indicate that the primary factor affecting the anodic nanostructure is the applied voltage, while anodization time and electrolyte concentration also play significant roles in tailoring the nanorod morphology.