Cation-exchange reaction between Ag+ and Cd2+ was employed to transform single-crystal Ag2Sc nanowires into single-crystal CdSe nanowires as a case study of transformation from one chalcogenide to another one. The CdSe nanowires of similar to 30 nm in diameter had a wurtzite crystal structure and showed preservation of both the morphology and single crystallinity of the Ag2Se nanowires. This synthetic route is useful in producing large quantities of CdSe nanowires with uniform diameters and exceptionally long lengths (> 50 mu m). (c) 2005 Elsevier B.V. All rights reserved.