We report a green synthesis of Cu(2)O nanowires and nanotubes in aqueous solution by reducing Cu(2+) to Cu(+) with glucose or fructose via Fehling's reaction. The screw dislocation-driven growth of Cu(2)O nanowires and nanotubes is confirmed by imaging the dislocation contrast, the Eshelby twist associated with dislocations and the spontaneously formed hollow nanotubes.