Aligned silicon carbide nanowires were synthesized directly from the silicon substrates via a novel catalytic reaction with a methane–hydrogen mixture at 1100 °C, with a mean diameter of 40 nm and length of 500 μm; they consist of a single-crystalline zinc blende structure crystal in the [111] growth direction; X-ray diffraction, Raman, and infrared spectroscopy confirm the synthesis of high-purity silicon carbide nanowires.