One of the most recent alternatives in the development of materials with high mechanical properties and wear resistance is the addition of nanometric and/or micrometric particles of a secondary phase into ceramic matrices. Nanostructured materials can be defined as systems that have at least one microstructural characteristic of nanometric dimensions (less than 100nm). In this work, alumina-diamond nanocomposites were produced using nanometric diamond powder obtained by high energy milling in a SPEX mixer mill for 6h. The crystallite size was 30nm. After deagglomeration, the diamond powder was added to the alumina matrix in a ratio of 5wt%. The samples were isostatically pressed and high-vacuum sintered. The resulting nanocomposites and composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and by microhardness, diametral compression and wear resistance tests. The results confirmed the promising wear characteristics of the alumina-diamond nanocomposite.