Polymeric gel electrolyte films consisting of poly(ethylene oxide)-based polyurethane containing lithium salt (LiClO4 or LiPF6) dissolved in propylene carbonate (PC) have been prepared. The ionic conductance and electrochemical properties of the gel films were examined. The obtained gel film was self-standing, transparent and flexible with high mechanical strength. Thermal analysis of the gel film showed that it is homogeneous and amorphous over a wide temperature range. The highest conductivity, 1.51mScm−1 at 60°C, was obtained for the polymeric gel containing 50wt.% of 1.5moldm−3 LiClO4/PC. The applicability of the present gel system to a rechargeable lithium battery was briefly examined by cyclic voltammetry and constant-current polarization using metallic lithium electrodes.