Metallic gold (Au) and silver (Ag) nanowire arrays coated with polythiophene (PTh) films were fabricated by successive electrochemical depositions of PTh and metal into the pores of a microporous alumina membrane. The diameter of the composite nanowires was 200 nm and that of the metallic nanowires was about 100 nm. They are adhered to a thin gold film and aligned in a high density of ca. 10(10) wires/cm(2). The morphology of the composite nanowires has been characterized by an optical microscope, Raman spectroscopy, scanning and transmission electron microscopies. Their electrochemical property has also been investigated. (C) 2003 Kluwer Academic Publishers.