The semiconductor nanowires are of special interest for their electronic, optical and conductive properties [1, 2]. Many methods have been developed to prepare semiconductor nanowires [3–5]. However, complicated apparatus, complex process control and special conditions may be required for these approaches. Here a new method for the preparation of cadmium oxide nanowires by calcining precursor powders containing cadmium carbonate, sodium chloride and potassium nitrate, previously prepared in a novel inverse microemulsion is reported. The method is distinguished by its simplicity of the apparatus used and the high efficiency of crystal growth. One of the simple preparation methods for a complex oxide is molten salt synthesis (MSS) [6], in which molten salts are used as solvents. In this method, the synthesis temperature and time are the process parameters, which lead to different results. Changes in the amount and type of salt can result in differences in powder characteristics because they are responsible for the reaction and growth environments. There are several requirements for the selection of the salt [6]. First, the melting point of the salt should be low and appropriate for the synthesis of the required phase; second, the salt should have sufficient aqueous solubility to enable it to be eliminated easily by simple washing after synthesis. Third, there should be no side reaction between the salt and the constituent oxides, which could result in undesirable second phases. Transparent conducting oxides have been studied extensively because of their importance in the fabrication of optoelectronic devices [7, 8]. Among the conducting oxides, cadmium oxide, a II–VI, n-type semiconductor, is one of the promising candidates for optoelectronic applications such as solar cells [9, 10], photo transistors [11], photo diodes [12] and transparent electrodes [13]. Applications of cadmium oxide have recently been extended to gas sensors [14] because of its ionic nature coupled with wide band gap (direct band gap of approximately 2.5 eV and indirect one experimentally found at 1.98 eV [15, 16]).