Measurement of the initial sintering shrinkage of CaAl2O4 at temperatures of 1300, 1325 and 1350 °C are reported. The particle sizes chosen were −53 + 45, −63 + 53 and −75 + 63 microns and the soaking periods were from 15 to 360 min. A time dependence of the shrinkage has shown that volume diffusion is the dominant mechanism of sintering. At any given time and temperature, the per cent shrinkage was found to be a decreasing function of particle size. The activation energy for the sintering of CaAl2O4 was found to be 766.38 KJ mol−1.