Here, we report on an in situ study of the spectroelectrochemical behavior of template prepared poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires by UV-Vis-NIR spectroscopy. A comparative analysis between spectra measured on a PEDOT thin film and on nanowires (diameter: 80 rims 30 nm) has been made. It gives evidence for - enhanced bipolaronic band in the oxidized state, and - more efficient dedoping in the reduced state, for the 30-nm nanowires. This result, analyzed in terms of higher (de)doping level during the redox process for the smaller diameter, demonstrates improved electroactivity and electrochromism, as required for sensors.