Hot-extrusion was used to produce Ni3Al-based alloys to which 10 vol% TiN, NbC, HfO2, or HfN was added for reinforcement. The TiN, NbC, and HfO2 particulates produced Ni3Al-matrix composites in which no reaction was noted at the particle-matrix interface. However, the addition of HfN resulted in extensive reaction in which the hafnium appeared to diffuse into the matrix. Microstructures of this alloy showed a complex array of phases and voids where the HfN particles are presumed to have been originally. Hot hardness, compression, and compression creep tests were performed on specimens cut from the extruded bar of each alloy. No significant strengthening was observed for the alloys containing TiN, NbC, or HfO2. However the HfN-containing alloy did show significant strengthening in simple compression and compression creep. This presentation will include microstructures and the results of the mechanical properties tests.