In this paper, bamboo-like 3C-SiC nanowires were synthesized in minutes without a metal catalyst by a simple, fast, and low-cost microwave method. The as-synthesized nanowires were studied by X-ray diffraction, scanning electron microscopy, Raman spectra, and transmission electron microscopy. The results showed that the bamboo-like nanowires have a stem of cubic 3C-SiC and nodes consisting of a high number of stacking faults, which are crystalline 3C-SiC with a diameter of 20-100 nm and a length around several microns. A possible mechanism for growing bamboo-like SiC nanowires in a microwave is also proposed.