A composite of polyaniline (PAn) with pumice (Pmc) was prepared via chemical oxidative polymerization of aniline in presence of a dispersion of pumice powders in water solvent using ammonium peroxydisulphate (APS) oxidant. Formation of PAn and its subsequent incorporation in the PAn/Pmc composite was confirmed by fourier transform infrared (FTIR) and X-ray diffraction (XRD) pattern analysis. Thermal analysis shows that PAn/Pmc composite is more thermally stable compared to PAn. Conductivity in PAn and PAn/Pmc was measured in heating-cooling cycles in the temperature range from 25 to 100 degrees C. Scanning electron microscopy was used for morphology study of surface of PAn and PAn/Pmc. High temperature conductivity measurements show "thermal activated behaviour". (c) 2006 Elsevier B.V. All rights reserved.