The crystal structure of the ordered double perovskite Sr 2MnTeO6 has been refined at ambient temperature from high resolution neutron and X-ray powder diffraction data in the monoclinic space group I 1 2/m 1 with a = 5.6166(1) Å, b = 5.5807(1) Å, c = 7.8797(1) Å and β = 90.048(2)°. The structure is the result of out-of-phase (-) rotations of virtually undistorted NiO6 and TeO 6 octahedra in the (0 - -) sense about two of the axes of the ideal cubic perovskite. Electron diffraction measurements have been used to confirm the proposed space group and structure.