The microstructures and mechanical properties of mechanically alloyed oxide dispersion strengthened tungsten heavy alloys were investigated. Elemental powders of tungsten (W), nickel (Ni), iron (Fe) and partially stabilized zirconia (PSZ) were mechanically alloyed by a planetary mill. Mechanically alloyed powders were consolidated by liquid phase sintering at temperature ranged 1465-1485 degrees C for I h in hydrogen atmosphere to obtain full densification. The W grain size decreases with increasing PSZ content. The oxide dispersoids were dispersed both within W grains and W/W and W/matrix interfaces. The yield strength of oxide dispersion strengthened tungsten heavy alloy was not dependent on PSZ content but dependent on microstructural factor, while the elongation decreases with increasing PSZ content. However, the high temperature yield strength increases with increasing content of PSZ dispersoid and the PSZ dispersoids act as the strengthening agent at high temperature deformation. (c) 2006 Elsevier B.V. All rights reserved.