Zinc oxide microrods (MRs) were successfully prepared without the addition of template and additive by a simple hydrothermal route using only Zn(CH3COO)(2)center dot 2H(2)O as a precursor at 160 degrees C for 3 h. Interestingly, the ZnO MRs can be transformed to ZnS microspheres (MSs) with the sulfur source of thiourea under the same conditions. The products were characterized by X-ray diffraction (XRD), energy-dispersive spectrum (EDS), and scanning electron microscopy (SEM). Results show that the obtained ZnO MRs and ZnS MSs belonged to hexagonal phase and cubic phase, respectively. A possible reaction mechanism is proposed and discussed.