Single-crystal ZnSe nanowires have been synthesized via a thermochemical method in a N-2 atmosphere with CO and H-2 gases. The as-prepared ZnSe nanowires have a mean diameter of 40 nm. and a length of 1 mum. The nanowires are single crystals with a hexagonal structure growing along the [0 0 1] direction. A self-catalyzed vapor-liquid-solid process is proposed for the formation of such nanowires. The as-prepared nanowires show two emission bands at ca. 447 and 617 nm. (C) 2003 Elsevier B.V. All rights reserved.