The effect of aluminium powder on the properties of natural rubber composites containing high abrasion furnace black (HAF), general purpose furnace black (GPF), acetylene black, china clay and precipitated silica was studied. In all cases the total filler content including aluminium powder is fixed at 40 parts per hundred rubber (phr). Gradual replacement of these fillers by aluminium powder showed a marked increase in thermal conductivity. This increased thermal conductivity of aluminium powder filled composites decreased the vulcanization time and led to uniform curing throughout the material especially for thick articles. Mechanical properties like tensile strength, tear strength, rebound resilience, heat build-up, hardness, compression set, etc, are comparatively better for these composites. Aluminium powder incorporated vulcanisates also showed good resistance against thermal aging and oxidative degradation. Thus, use of aluminium powder in rubber compounds can lead to energy saving in the vulcanization of thick rubber articles and enhance the service life of such rubber products.