Single-crystal CdSe nanorods (10011 orientation) with diameters in the range of 40-60 mm and aspect ratios of 5-8 were successfully synthesized at 180 degrees C for 10 h through a facile surfactant-assisted hvdrothermal method, using Na2SeO3 as a high-quality soluble selenium source. The products were characterized by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, and ultraviolet-vis spectra analysis. It was found that the surfactant (cetyltrimethyl ammonium bromide) played a vital role in the process. Through varying the concentrations of surfactant, the morphologies changed from dendrite-like nanostructure to nanorods, short nanorods, and nanoparticles. The possible mechanism for the growth of CdSe nanocrystals was also discussed.