In this work, a new hydrothermal process is described, in which, for the first time, an aquatic Zn2+ precursor is used for the synthesis of high aspect ratio ZnO particles, without the presence of any organic additive. Characterization of the particles is carried out by XRD, TEM, and SAED. Also the influence of different reaction times and of another reaction medium on the morphology and the dimensions of the rods is investigated.