Alumina-based nanocomposite powders with tungsten carbides particulates were synthesized by ball milling WO3, Al and graphite powders. X-ray Diffraction (XRD) was used to characterize the milled and annealed powders. Microstructures of milled powders were studied by Transmission Electron Microscopy (TEM). Results showed that Al2O3-W2C composite formed after 5 h of milling with major amount of un-reacted W in stainless steel cup. The remained W was decreased to minor amount by increasing carbon content up to 10 wt.%. When milled with ZrO2 cup and balls, Al2O3-W2C composite was completely synthesized after 20 h of milling with the major impurity of ZrO2. In the case of stainless steel cup and balls with 10 wt.% carbon, Fe impurity after 5 h of milling (maximum 0.09 wt.%) was removed from the powder by leaching in 3HCl center dot HNO3 solution. The mean grain size of the powder milled for 5 h was less than 60 nm. The powder preserved its nanocrystalline nature after annealing at 800 degrees C. (C) 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.