Here, we described a novel synthetic method of PVP (poly(N-vinyl-2-pyrrolidone))-coated GeO2 nanoparticles by a simple procedure, and its fabrication into a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) film. Interestingly, PEDOT-PSS films containing a small amount of PVP-coated GeO2 nanoparticles exhibited higher electrical conductivity than pure PEDOT-PSS. Finally, we have succeeded in the development of a new organic-inorganic thermoelectric conversion film with high performance.