We report electrical conductivity of Ti-nanowires in sapphire fabricated by utilizing lattice dislocations. We evaporated metallic Ti on a sapphire plate containing high density of uniaxial dislocations, and annealed the plate at high temperatures. As a result, it was found that Ti atoms intensely segregated along the dislocations within about 5 nm in diameter, indicating the formation of Ti-nanowires inside sapphire. Furthermore, the nanowires were confirmed to have significant electrical conductivity even in sapphire insulator. (C) 2004 Elsevier B.V. All rights reserved.