The ball milling of powders is a non-equilibrium technique (similar to rapid solidification processes) that can be used for production and structural modification of materials. Carbon nanotubes (CNTs) are relatively new materials with excellent combination of properties. They are one of the advanced reinforcement materials for engineering composites. Besides the polymer and ceramic matrices, interests are growing recently on the metallic matrices such as aluminum alloys for potential structural applications. Mechanical alloying (MA) is one of the best processing methods for synthetizing Al/CNTs nanocomposites, which results in the uniform dispersion of the reinforcement, inhibits the formation of undesired phases, and produces a nanostructured microstructure. It is of great importance to understand the mechanical alloying of Al/CNTs powder mixture for preparing nanocomposites. As a result, the current paper deals with the basics of the MA process, preparation of nanocomposites by MA, and summarizing the current knowledge on Al/CNTs nanocomposites processed by MA. Manuscript profile