Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is one of the most promising electro conductive polymers that can be used for thermoelectric (TE) materials. As in a liquid form this material is beneficial for preparation of TE nanocomposites with enhanced TE properties by adding conductive and inorganic TE fillers thus improving its potential. By now PEDOT:PSS fillers include carbon nanotubes and nano-sized inorganic TE particles [1,2]. In this work PEDOT:PSS was modified with multi-walled carbon nanotubes (MWCNTs) to improve Seebeck coefficient and further improvements were made by modification with Sb2Te3 synthesized on MWCNT surface. All fillers at different weight concentrations were mixed in PEDOT:PSS by using ultrasonic probe and samples were obtained by drop coating method on a 25×25 mm glass surface.