Mixed-oxide prepared Ca0.7Ti0.7La0.3Al0.3O3 (CTLA) ceramics (approximate to 96% dense), grain size 6-7 mu m, with dielectric properties (at 4 GHz) of epsilon(r)approximate to 46, Q x f approximate to 38 000 GHz, and tau(f)+13 ppm/degrees C, were studied at 25 degrees-1300 degrees C using synchrotron X-ray powder diffraction. At room temperature, CTLA exhibits a distorted orthorhombic structure, with two tilt systems: a=5.40383 (4) angstrom, b=5.41106 (6) angstrom, and c=7.64114 (7) angstrom with space group Pbnm. At 1050 degrees +/-25 degrees C, there is a transition from orthorhombic (Pbnm) to tetragonal (I4/mcm), with a simpler tilt arrangement. The lattice parameters at 1100 degrees C were: a=5.44285 (4) angstrom and c=7.68913 (8) angstrom.