The computational study of heat transfer and fluid flow in a porous media cold plate was investigated using lattice Boltzmann method. The study was carried out on a heat exchanger including two adiabatic inlet and outlet conduit and three hot fins with constant temperature. The porous medium is positioned between the fins to enhance heat transfer rate. The local thermal equilibrium assumption between the fluid and solid phases and the Brinkman–Forchheimer extended Darcy equation was used to simulate the porous domain. The effect of porosity on heat transfer from the fins surfaces was studied at different Reynolds and Prandtl numbers. Results show that by decreasing the porosity, the heat transfer rate increases and the fluid bulk temperature grows at less time for different Reynolds and Prandtl numbers.