Alumina-yttrium aluminum garnet (YAG) 50 vol % nanocomposite powders were prepared by a wet-chemical synthesis and characterized by simultaneous DTA-TG, XRD, and TEM analyses. Amorphous powders were preheated at four different temperatures (namely, 600, 800, 900, and 1215°C) on the basis of the previous characterization, and the influence of this thermal treatment on sintering behavior, final microstructure, and density was investigated.