The temperature-dependent thermo-physical and mechanical properties of a pultruded E-glass fiber-reinforced polyester (GFRP) composite are investigated in this paper. Fitting of theoretical models of the material properties to results of TGA, DSC, hot disk, and DMA experiments demonstrated good agreements. The constants for an Arrhenius representation of the decomposition mass-loss were determined using multi-curves methods. The effective specific heat capacity for the virgin material was found to increase during the decomposition process. A series model based on component volume fraction during decomposition provided an accurate description of the thermal conductivity as a function of temperature as measured by hot disk. Models based on the kinetic theory can describe the material degradation during glass transition as indicated by DMA results, while the parameters still need to be accurately identified. This paper provides a full set of temperature-dependent physical properties of a polyester matrix composite and demonstrates the applicability of theoretical models to represent the experimental results. © 2008 Elsevier B.V. All rights reserved.