In this work, perovskite-type SrCeO3 nanoparticles were used for improving the properties of high temperature polybenzimodazole (PBI) based proton exchange membranes. Novel proton conducting membrane nanocomposites were prepared using different amounts of SrCeO3 nanopowders dispersed into PBI by solution casting method. The nanocomposite membranes were studied by using AC impedance spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray and thermo gravimetric analysis. The prepared nanocomposite membranes showed a higher acid uptake, proton conductivity and thermal stability compared with the pure PBI membranes. The highest acid uptake (190%) and proton conductivity (0.105 S/cm at 180 degrees C and 0% RH) were observed for phosphoric acide-dopped PBI nanocomposite membranes containing 8 wt% of SrCeO3 nanoparticles (PSC8). The PSC8 nanocomposite membranes were tested in a fuel cell and the polarization and power curves were obtained at different temperatures. The PSC8 showed 0.44 W/cm(2) power density and 0.88 A/cm(2) current density in 0.5 V at 180 degrees C. The result obtained from our studies shows the enhanced potential of the PSC8 as proton exchange membranes for high temperature proton exchange membrane fuel cells. (C) 2014 Elsevier Ltd. All rights reserved.