Polymer blending is used to overcome the disadvantage of pure starch film, and in the present study, starch has been blended with poly(ethylene oxide) (PEO). The X-ray diffraction study shows that starch/PEO with a ratio of 7 : 3 exhibits the least amount of crystallinity, and this was chosen in the preparation of polymer electrolyte. Films of starch/PEO blends were then prepared via solution casting technique, and their properties with different amounts of ammonium nitrate NH4NO3were compared. The highest conductivity at room temperature of ?2�81�0� 46�107S cm-21was achieved with the addition of 35 wt-%NH4NO3. Dielectric data were analysed using complex permittivity and complex electrical modulus for the sample with the highest ionic conductivity. The relaxation time ? for these samples was determined, and the plot shows that t decreases with conductivity of the complexes. The presence of peaks in the imaginary plots shows that the starch/ PEO electrolyte system is an ionic conductor. � W. S. Maney & Son Ltd. 2011.