The use of ultrafine powders in dense ceramics production, minimizing the grain size, has shown an increasing interest due the improvement upon several properties. A peculiarity of these powders is the mechanisms acting during initial stages of sintering. In this paper, high-energy milling was used to prepare nanometric; particle size alumina from commercial alumina powder. The powders were characterized by determination of XRD crystallite size, specific surface area and high resolution SEM. The microstructural evolution during sintering was analyzed using measurements of density, BET surface area and grain size distribution, determined by high resolution SEM. The milling process results in lower temperatures of beginning of densification and the beginning of grain growth at higher densities during sintering, however the final results at maximum densities are similar. The high specific surface area obtained by milling is completely eliminated with a heat treatment at 900degreesC due a low temperature process of coarsening of the crystallites and the densification of the crystallite.