This paper presents an analytical study of the forced convection heat transfer characteristics in high porosity open-cell metal-foam filled pipes. The Brinkman-extended Darcy momentum model and two-equation heat transfer model for porous media were employed. Based on the analytical solutions, the velocity and temperature distributions in metal-foam filled pipes were obtained. The effects of the microstructure of metal foams on overall heat transfer were examined. The results show that the pore size and porosity of metal-foams play important roles on overall heat transfer performance. The use of metal-foam can dramatically enhance the heat transfer but at the expense of higher pressure drop. (c) 2006 Elsevier Ltd. All rights reserved.