The structure of La2NiRuO6 is studied with conventional X-ray and synchrotron-radiation diffraction methods. The obtained results show that this compound has a double perovskite structure with ordered arrangement of the B-site cations and P2(1)/n space group. High-temperature diffraction measurements show that this structure is preserved up to 900 degreesC. (C) 2003 Elsevier Ltd. All rights reserved.