The La2-xNdxMo2O9 (x = 0.4, 0.6, 0.8, 1.0) ceramics were successfully synthesized via the sol-gel method. Structural and microstructural analyses revealed that all the samples crystallize in the cubic phase and exhibit dense microstructures, although their particle sizes vary. Dielectric, impedance, and electric modulus spectroscopic analyses revealed two relaxation processes in both the temperature and the frequency spectra. Further investigation clarified that the two relaxation processes are associated with grain and grain-boundary relaxation. At temperatures less than 683 K, the bulk response is a localized relaxation process, whereas long-range conductivity dominates when the temperature is increased to 713 K. (C) The Author(s) 2016. Published by ECS. All rights reserved.