SUMMARYSteady two-dimensional free convection flow due to combined effect of radiation and convection through a porous medium bounded by a vertical infinite plate is considered. The behaviour of Darcy and non-Darcy flow is investigated. The flow of water through different porous media under different environmental conditions is discussed. Effect of four non-dimensional parameters, i.e. Prandtl number (Pr), modified Grashof number (G), permeability parameter (K) and radiation parameter (N ) has been studied. Effect of these parameters on Nusselt number is analysed.