High-quality, crystalline AlN whiskers with large yield have been synthesized through the direct nitridation of Al vapor at high temperature. The AlN whiskers exhibited a strong and uniform ultraviolet emission at approximately 352 nm, which is notably shorter compared with the wavelength of previously reported one-dimensional AlN nanostructures. Energy filtered transmission electron microscope (TEM) analyses indicated that nitrogen deficiency and rather lower oxygen content in the AlN lattice might be responsible for the strong 352 nm ultraviolet emission.