Recently, the organic/inorganic hybrid materials with flexibility, thermal, and chemical stabilities are extensively studied for the application of temperature tolerant polymer electrolyte fuel cells. This paper reports the preparation and properties of sol-gel derived proton conducting organic/inorganic materials based on zirconia bridged hydrocarbon phosphotungstic acids. The materials are molecular hybrids where linear hydrocarbons such as trimethylene glycols (TMGs) or octamethylene glycols (OMGs) are covalently bonded to zirconia interface to form macromolecular organic/inorganic networks. The hybrid materials become proton conducting polymer electrolytes by the addition of 12-phosphotungstic acids. The hybrid materials showed high thermal stability, and high protonic conductivity of 4 X 10(-3) S cm(-1) under saturated humidity condition at 150 degreesC. The materials can be expected to be used for the application of temperature tolerant polymer electrolyte fuel cell. (C) 2004 Elsevier Ltd. All rights reserved.