Most materials tend to cavitate during deformation and cavitation damage is responsible for the premature failure of materials. Cavitation failure in materials occurs by the nucleation, growth, and coalescence of voids. The presence of cavities in deformed components can adversely affect their mechanical properties and lead to the degradation of in service properties. In the present study, the effect of alumina content on cavity formation during high temperature deformation in a 3YTZP (3 mol.-% yttria stabilised ZrO2)/Al2O3 composite has been quantitatively examined. Also, the distribution of cavity size and cavity orientation have been determined as a function of strain, strain rate, and temperature using a 3YTZP/Al2O3 composite containing 20 wt-%Al2O3. It was seen from experiments that extensive internal cavities formed during high temperature deformation and the amount of cavitation increased with increasing alumina content, strain, and strain rate, and with decreasing temperature.