Magnesiumchromite, MgCr2O4, undergoes a structural transition from a cubic spinel structure [space group Fd3m, a=8.32768(4) Å at 16 K] into a tetragonal distorted structure [space group I41/amd, a=5.89199(5) Å, c=8.31677(8) Å at 10 K], isotypic with Hausmannite, Mn3O4. This phase transition is translationengleich and takes place very close or at the antiferromagnetic ordering temperature.