Metal matrix composites (MMCs) reinforced with nano-particles which called Nanocomposites (MMNCs), are ex-tensively studied in the recent years. Nanocomposites present high strength, wear resistance, hardness and exception- al microstructure stability. The nano-particles can improve the base material in terms of wear resistance, damping properties and mechanical strength. In this paper the tribological behavior of A356/Al2O3 nanocomposites were in- vestigated at room temperatures under dry sliding conditions. The results showed that the wear rate of the A356 alloy was significantly improved by the addition of the Al2O3 nano-particles. The wear rate of the nanocomposites was re- duced to about 25% (for nanocomposites containing 5 vol.-% of nano-particles) of the wear rate of the A356 mono- lithic alloy.