In the present study, magnesium based composites were fabricated with three different types of 1.1 volume percent nanosize oxide particulate reinforcements (i.e., Al2O3, Y2O3 and ZrO2) using blend-press-sinter methodology avoiding ball milling. Microstructural characterization of the materials revealed reasonably uniform distribution of nano-reinforcement, significant grain refinement and the presence of minimal porosity. Mechanical properties characterization revealed that the incorporation of nano-sized oxide particulates as reinforcement led to a simultaneous increase in hardness, 0.2% yield strength, UTS and ductility of pure magnesium. The results further revealed that the 0.2% yield strength, UTS and ductility combination of the magnesium containing nano-size Al2O3 remained higher when compared to high strength magnesium alloy AZ91 reinforced with much higher amount of micron size SiC particulates. An attempt is made in the present study to correlate the effect of different types of nano-sized oxide particulates on the microstructural and mechanical properties of magnesium. (c) 2006 Springer Science + Business Media, Inc.