The powder solution composite (PSC) method was used to obtain the conductivity of ZnO nanowires from impedance spectroscopy measurements of ZnO nanowires dispersed in solution. The PSC method was calibrated by comparing impedance spectroscopy measurements of ZnO powder dispersed in solution with four-point probe measurements on bulk ZnO ceramic pellets. Conductivity values for ZnO nanowires obtained using this novel approach were found to be comparable to reported values obtained using two-point and four-point probe measurements of single or multiple nanowire devices isolated on a substrate. It is shown that application of the PSC method to ZnO nanowire solutions avoids the difficult process of forming electrical contacts to nanowires and allows for the non-destructive in-situ measurement of the average electrical properties of a large quantity of nanowires. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3615844] All rights reserved.