In this article, an inverse analysis for simultaneous estimation of temperature dependent thermal conductivity (k(T)) and specific heat capacity (Cp(T)) of isotropic solids is presented. The unknown thermal properties are assumed a parametric variation with temperature and these parameters are then estimated from the solution of inverse problem. Pseudo-experimental temperature data are used to study the robustness of the present inverse parameter estimation solution strategy. Due to lack of sensitivity and existence of correlation among the unknown parameters, the solution to inverse problem is carried out with Levenberg–Marquardt, Genetic Algorithm (GA) and hybrid GA and it is found that hybrid GA is more suitable for this parameter estimation problem. The proposed inverse approach is also extended to real-time experiments involving heating of mild steel (MS) and stainless steel (SS304) samples with concentrated solar thermal energy source. The estimated constant k and Cp for MS are found to be 52.6 W/m-K and 507.24 J/kg-K respectively which are within 10% deviation from the literature data. Similarly, the estimated k and Cp of SS304 at 360 K are found to be 16.75 W/m-K and 512.7 J/kg-K with an absolute deviation of 6% and 4% respectively from literature data. © 2020 Elsevier Ltd