A three-dimensionally ordered macroporous (3DOM) ternary oxide, CsAlTiO 4 , with a framework related to ‘stuffed-tridymite’ has been synthesized at temperatures 500–700°C using a sol–gel precursor solution and templating with polystyrene spheres. The 3DOM material displayed pore diameters of 0.5–0.8μm with the walls composed of anhedral and acicular CsAlTiO 4 crystals whose dimensions ranged from 16 to 25nm. Microanalysis confirmed near-stoichiometric proportions (1:1:1) of Cs, Al and Ti. The effect of sintering temperature on the macroporous structure and on the CsAlTiO 4 walls was studied. As the sintering temperature increased from 500 to 600°C the unit cell parameters varied through dilation (a and b) and contraction (c-axis), followed by a reversal of these trends from 700 to 900°C. This behaviour in non-equilibrated CsAlTiO 4 can be attributed to distortion of the (Al, Ti)O 4 tetrahedral framework, however at the highest temperature the cell constants stabilized close to those reported for single crystal CsAlTiO 4 . X-ray amorphous content was significant in all materials varying from 73wt% after 500 o C and reducing to 44wt% at 900°C.