This study examined pressure consolidation of amorphous Al2O3-15 mol% Y2O3 powders prepared by co-precipitation and spray pyrolysis. The two amorphous powders had similar true densities and crystallization sequences. Uniaxial hot pressing was carried out at 450 degrees-600 degrees C with a moderate pressure of 750 MPa. The co-precipitated powder could be hot pressed to a maximum relative density of 98% and remained amorphous. Pressure adversely affected the densification of the spray-pyrolyzed powder by favoring an early crystallization of gamma-Al2O3 phase at 580 degrees C. Plastic deformation of the amorphous phase is believed to be responsible for the large densification of the amorphous powders.