This work presents an efficient technique to improve compressibility and thermal properties of Al-Al2O3 nanocomposites. The compressibility behavior was examined by cold compaction test, and the thermal conductivity was calculated through the measured electrical resistivity of the prepared samples. The results showed that the addition of Al2O3 to Al matrix improves the compressibility behavior of the produced nanocomposite. However, it has a negative effect on the thermal conductivity of the produced composite. Adding Al2O3 hard particles accelerates the fracturing process which improves the compressibility behavior. However, it causes some agglomeration at the grain boundaries which reduce the thermal conductivity. The addition of Mg to Al-Al2O3 nanocomposite improves both the compressibility behavior and the thermal conductivity. This is due to the great reduction in the particle size and the agglomeration of reinforcement particles on the grain boundaries which improve the compressibility behavior and the thermal conductivity.