A novel approach has been described for the synthesis of zinc oxide nanoparticles by a very simple reaction of zinc metal with ethanol at 100oC. The diameters of the nano-particles range from 50–100nm. The reaction involves the cleavage of C-O bond of the alcohol, which occurs readily on zinc metal surface. Addition of ethylenediamine to the reaction yields nanorods, thus acting as a shape directing agent. A plausible mechanism is proposed for the formation of these nanostructures and is expected that this synthetic technique can be extended to obtain other metal oxides.