A composite polymer electrolyte of polyethyleneoxide-LiBF4 containing fine particles of zeolite was studied using electrochemical impedance spectroscopy, cyclic voltammetry, differential scanning calorimetry, infrared spectroscopy and scanning electron microscopy. When compared with the polymer electrolyte without zeolite, the specific conductivity of the composite electrolyte film is higher by about two orders of magnitude at room temperature. The increase in specific conductivity is explained as due to increased amorphocity which is reflected in the thermal studies. The nature of the cyclic voltammograms and infrared spectra is discussed.