Potassium niobate (KNbO3) nanorods were prepared from Nb2O5 powder by hydrothermal synthesis in KOH solution at 180 degrees C for 48 h using sodium dodecyl sulfate surfactant. The products were characterized by X-ray diffraction as well as scanning and transmission electron microscopy. The KNbO3 nanorods were shown to have orthorhombic crystal structure and were 100-300 nm in diameter and up to 5 microm long. The addition of surfactant changed the product morphology from agglomerated particles to nanorods. A possible mechanism for the formation of the KNbO3 nanorods is briefly discussed.