Indium oxide (In2O3) nanowires have been recently synthetized and interesting properties and applications in gas-sensors and optoelectronic fields have been suggested. In order to reduce as much as possible the influence of undesired dopants and/or impurities on the observed properties, In2O3 nanowires have been grown without the use of catalysts, directly from metallic indium by a vapor transport technique and a controlled oxidation with oxygen-argon mixtures. Depending on the growth conditions (temperature, vapor pressure, oxygen concentration, etc.) different results have been achieved and it has been observed that a 'proper' In condensation on the substrates may enhance the nanowires growth. (C) 2007 Elsevier B.V. All rights reserved.