Suspended nanowires (SNWs), 600 nm-long, 20 nm-wide and 30 nm-thick, were grown by electron beam-induced deposition of metallorganic Pt, with and without water vapour assistance, and electrically characterized at room temperature. SNWs have Ohmic behaviour in the (-0.1, 0.1 V) range, and show conductivity improvement and structural evolution as subsequent I-V cycles are applied; both effects being enhanced by water vapour assistance. Typical resistivities after two I-V cycles are 1-3 x 10(-4) Omega m and 6-8 x 10(-5) Omega m, for Pt and (Pt + water) depositions, respectively. Structural evolution consists of a progressive coalescence of the Pt nanocrystals into large (15-20 nm) and separated grains, leaving wide regions essentially made of carbon material. I-V characteristics over an extended (-2, 2 V) range show a non-linear behaviour outside the (-0.4, 0.4 V) interval, with currents up to similar to 90 mu A at 2 V, corresponding to current densities of similar to 1 x 10(7) A/cm(2). (C) 2008 Elsevier B.V. All rights reserved.}