In this study, the effect porosity on thermal conductivity of powder metal materials have been investigated. Metal powders produced from Hoganas ASC 100.29 which have been compacted in 245, 290, 368 MPa pressures and sintered at 900, 1025, 1150 degrees C temperatures. As-received samples had various porosity. Thermal conductivity of these materials was measured and it was observed that thermal conductivity decreases with porosity rate in PM materials. Change of the thermal conductivity in PM materials due to porosity is also discussed. (c) 2005 Published by Elsevier Ltd.