Thermal studies on CuCr2O4 spinel indicated the phase present above 870 K to be cubic CuCr2O4. However, when the substance was quenched from 1023 K, 1173 K, 1273 K and 1473 K, only the tetragonal phase of CuCr2O4 was obtained. This is because the first-order, diffusionless, tetragonal to cubic phase transition at 865 K occurs reversibly at a very fast rate. Thec/a ratio for CuCr2O4 present in the various quenched samples did not change when the quenching temperature was raised. A strong preference of the Cr3+ ion for the B site prevents it from interchanging sites with Cu2+ ions, thus keeping the lattice parametersc anda unchanged.