An ion conducting polymer nanocomposite electrolyte (PNCE) series of film based on an amorphous polymer host (PMMA)-lithium salt (LiClO4) complex dispersed with nanocrystalline yttria stabilized zirconia (n-YSZ) is reported. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis have confirmed feasibility of interaction among composite components (i.e. polymer-ion-filler). Ions in the PNCE matrix are present in the form of both free cations/anions as well as contact ion pairs and their concentration depends on filler loading in the matrix. Electrical conductivity enhancement on n-YSZ dispersion occurs by similar to 2 orders of magnitude at 30 degrees C and by similar to 5 orders of magnitude at 100 degrees C when compared with room temperature conductivity of the undispersed polymer salt (PS) film. The highest achieved conductivity value is similar to 1.3 9 10(-4) S cm(-1) at 100 degrees C for 2 wt% n-YSZ. An excellent correlation between variation of d.c. conductivity and free mobile charge carriers versus filler loading has been observed. This correlation has been attributed to filler-induced polymer-ion-filler interaction. These evidences have formed the basis to propose a mechanism for ion transport.