Fe-doped ZnO rod arrays have grown on zinc foils by the hydrothermal method at temperature of 180 °C. The doping Fe content can be controlled by varying the reaction time. X-ray diffraction and X-ray photoelectron spectroscopy results provide the evidence that Fe3+ is incorporated into the ZnO lattices. Photoluminescence spectrum of the rod arrays shows that the emission peak shifts a little to lower energy and its intensity decreases with the increase of Fe content. The green emission resulting from oxygen vacancy is observed when excessive Fe ions are doped in ZnO. The rod arrays have exhibited room-temperature ferromagnetic behavior with the remanence of 0.293, 0.613 and 0.557 emu/cm3 for the Fe concentration of 0.50, 1.22 and 2.00 at%, respectively. The exchange interaction between local spin-polarized electrons and conductive electrons is proposed as a cause of the room-temperature ferromagnetism.