In the present study, numerical investigation of jet impingement cooling of a constant heat flux horizontal surface immersed in a confined porous channel is performed under mixed convection conditions with the limitation of the Darcy model. The results are presented in the mixed convection regime with wide ranges of the governing parameters: Peclet number (1 <= Pe <= 1000), Rayleigh number (10 <= Ra <= 100). half jet width (0.1 <= D <= 1.0), and the distance between the jet and the heated portion (0.1 <= H <= 1.0). It is found that the average Nusselt number increases with increase in either Rayleigh number or jet width for high values of Peclet number. The average Nusselt number also increases with decrease in the distance between the jet and the heated portion. The correlation for Nu(avg) in the forced convection regime is suggested. It is shown that mixed convection mode can cause minimum average Nusselt number unfavorably due to counteraction of jet flow against buoyancy driven flow. Hence, careful consideration must be given while designing a system of jet impingement cooling through porous medium. (C) 2010 Elsevier Ltd. All rights reserved.